diff --git a/docs/source/en/_toctree.yml b/docs/source/en/_toctree.yml
index e72f674bfbd7..684dbd4620fa 100644
--- a/docs/source/en/_toctree.yml
+++ b/docs/source/en/_toctree.yml
@@ -426,6 +426,8 @@
       title: ScoreSdeVeScheduler
     - local: api/schedulers/score_sde_vp
       title: ScoreSdeVpScheduler
+    - local: api/schedulers/ufogen
+      title: UFOGenScheduler
     - local: api/schedulers/unipc
       title: UniPCMultistepScheduler
     - local: api/schedulers/vq_diffusion
diff --git a/docs/source/en/api/schedulers/ufogen.md b/docs/source/en/api/schedulers/ufogen.md
new file mode 100644
index 000000000000..45572434927c
--- /dev/null
+++ b/docs/source/en/api/schedulers/ufogen.md
@@ -0,0 +1,15 @@
+# UFOGen Multistep and Single-Step Scheduler
+
+## Overview
+
+Multistep and onestep scheduler introduced with the UFOGen model in the paper [UFOGen: You Forward Once Large Scale Text-to-Image Generation via Diffusion GANs](https://arxiv.org/abs/2311.09257) by Yanwu Xu, Yang Zhao, Zhisheng Xiao, and Tingbo Hou.
+This scheduler should be able to generate good samples from a UFOGen model in 1-4 steps.
+
+<Tip warning={true}>
+
+Multistep sampling support is currently experimental.
+
+</Tip>
+
+## UFOGenScheduler
+[[autodoc]] UFOGenScheduler
diff --git a/src/diffusers/__init__.py b/src/diffusers/__init__.py
index c43000e27b82..0c4e0713bbdc 100644
--- a/src/diffusers/__init__.py
+++ b/src/diffusers/__init__.py
@@ -154,6 +154,7 @@
             "RePaintScheduler",
             "SchedulerMixin",
             "ScoreSdeVeScheduler",
+            "UFOGenScheduler",
             "UnCLIPScheduler",
             "UniPCMultistepScheduler",
             "VQDiffusionScheduler",
@@ -529,6 +530,7 @@
             RePaintScheduler,
             SchedulerMixin,
             ScoreSdeVeScheduler,
+            UFOGenScheduler,
             UnCLIPScheduler,
             UniPCMultistepScheduler,
             VQDiffusionScheduler,
diff --git a/src/diffusers/schedulers/__init__.py b/src/diffusers/schedulers/__init__.py
index 40c435dd5637..c382f3510e07 100644
--- a/src/diffusers/schedulers/__init__.py
+++ b/src/diffusers/schedulers/__init__.py
@@ -61,6 +61,7 @@
     _import_structure["scheduling_pndm"] = ["PNDMScheduler"]
     _import_structure["scheduling_repaint"] = ["RePaintScheduler"]
     _import_structure["scheduling_sde_ve"] = ["ScoreSdeVeScheduler"]
+    _import_structure["scheduling_ufogen"] = ["UFOGenScheduler"]
     _import_structure["scheduling_unclip"] = ["UnCLIPScheduler"]
     _import_structure["scheduling_unipc_multistep"] = ["UniPCMultistepScheduler"]
     _import_structure["scheduling_utils"] = ["KarrasDiffusionSchedulers", "SchedulerMixin"]
@@ -151,6 +152,7 @@
         from .scheduling_pndm import PNDMScheduler
         from .scheduling_repaint import RePaintScheduler
         from .scheduling_sde_ve import ScoreSdeVeScheduler
+        from .scheduling_ufogen import UFOGenScheduler
         from .scheduling_unclip import UnCLIPScheduler
         from .scheduling_unipc_multistep import UniPCMultistepScheduler
         from .scheduling_utils import KarrasDiffusionSchedulers, SchedulerMixin
diff --git a/src/diffusers/schedulers/scheduling_ufogen.py b/src/diffusers/schedulers/scheduling_ufogen.py
new file mode 100644
index 000000000000..9a4d35fe701b
--- /dev/null
+++ b/src/diffusers/schedulers/scheduling_ufogen.py
@@ -0,0 +1,525 @@
+# Copyright 2023 UC Berkeley Team and The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# DISCLAIMER: This file is strongly influenced by https://github.com/ermongroup/ddim
+
+import math
+from dataclasses import dataclass
+from typing import List, Optional, Tuple, Union
+
+import numpy as np
+import torch
+
+from ..configuration_utils import ConfigMixin, register_to_config
+from ..utils import BaseOutput
+from ..utils.torch_utils import randn_tensor
+from .scheduling_utils import SchedulerMixin
+
+
+@dataclass
+# Copied from diffusers.schedulers.scheduling_ddpm.DDPMSchedulerOutput with DDPM->UFOGen
+class UFOGenSchedulerOutput(BaseOutput):
+    """
+    Output class for the scheduler's `step` function output.
+
+    Args:
+        prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
+            Computed sample `(x_{t-1})` of previous timestep. `prev_sample` should be used as next model input in the
+            denoising loop.
+        pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
+            The predicted denoised sample `(x_{0})` based on the model output from the current timestep.
+            `pred_original_sample` can be used to preview progress or for guidance.
+    """
+
+    prev_sample: torch.FloatTensor
+    pred_original_sample: Optional[torch.FloatTensor] = None
+
+
+# Copied from diffusers.schedulers.scheduling_ddpm.betas_for_alpha_bar
+def betas_for_alpha_bar(
+    num_diffusion_timesteps,
+    max_beta=0.999,
+    alpha_transform_type="cosine",
+):
+    """
+    Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of
+    (1-beta) over time from t = [0,1].
+
+    Contains a function alpha_bar that takes an argument t and transforms it to the cumulative product of (1-beta) up
+    to that part of the diffusion process.
+
+
+    Args:
+        num_diffusion_timesteps (`int`): the number of betas to produce.
+        max_beta (`float`): the maximum beta to use; use values lower than 1 to
+                     prevent singularities.
+        alpha_transform_type (`str`, *optional*, default to `cosine`): the type of noise schedule for alpha_bar.
+                     Choose from `cosine` or `exp`
+
+    Returns:
+        betas (`np.ndarray`): the betas used by the scheduler to step the model outputs
+    """
+    if alpha_transform_type == "cosine":
+
+        def alpha_bar_fn(t):
+            return math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2
+
+    elif alpha_transform_type == "exp":
+
+        def alpha_bar_fn(t):
+            return math.exp(t * -12.0)
+
+    else:
+        raise ValueError(f"Unsupported alpha_tranform_type: {alpha_transform_type}")
+
+    betas = []
+    for i in range(num_diffusion_timesteps):
+        t1 = i / num_diffusion_timesteps
+        t2 = (i + 1) / num_diffusion_timesteps
+        betas.append(min(1 - alpha_bar_fn(t2) / alpha_bar_fn(t1), max_beta))
+    return torch.tensor(betas, dtype=torch.float32)
+
+
+# Copied from diffusers.schedulers.scheduling_ddim.rescale_zero_terminal_snr
+def rescale_zero_terminal_snr(betas):
+    """
+    Rescales betas to have zero terminal SNR Based on https://arxiv.org/pdf/2305.08891.pdf (Algorithm 1)
+
+
+    Args:
+        betas (`torch.FloatTensor`):
+            the betas that the scheduler is being initialized with.
+
+    Returns:
+        `torch.FloatTensor`: rescaled betas with zero terminal SNR
+    """
+    # Convert betas to alphas_bar_sqrt
+    alphas = 1.0 - betas
+    alphas_cumprod = torch.cumprod(alphas, dim=0)
+    alphas_bar_sqrt = alphas_cumprod.sqrt()
+
+    # Store old values.
+    alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
+    alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
+
+    # Shift so the last timestep is zero.
+    alphas_bar_sqrt -= alphas_bar_sqrt_T
+
+    # Scale so the first timestep is back to the old value.
+    alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
+
+    # Convert alphas_bar_sqrt to betas
+    alphas_bar = alphas_bar_sqrt**2  # Revert sqrt
+    alphas = alphas_bar[1:] / alphas_bar[:-1]  # Revert cumprod
+    alphas = torch.cat([alphas_bar[0:1], alphas])
+    betas = 1 - alphas
+
+    return betas
+
+
+class UFOGenScheduler(SchedulerMixin, ConfigMixin):
+    """
+    `UFOGenScheduler` implements multistep and onestep sampling for a UFOGen model, introduced in
+    [UFOGen: You Forward Once Large Scale Text-to-Image Generation via Diffusion GANs](https://arxiv.org/abs/2311.09257)
+    by Yanwu Xu, Yang Zhao, Zhisheng Xiao, and Tingbo Hou. UFOGen is a varianet of the denoising diffusion GAN (DDGAN)
+    model designed for one-step sampling.
+
+    This model inherits from [`SchedulerMixin`] and [`ConfigMixin`]. Check the superclass documentation for the generic
+    methods the library implements for all schedulers such as loading and saving.
+
+    Args:
+        num_train_timesteps (`int`, defaults to 1000):
+            The number of diffusion steps to train the model.
+        beta_start (`float`, defaults to 0.0001):
+            The starting `beta` value of inference.
+        beta_end (`float`, defaults to 0.02):
+            The final `beta` value.
+        beta_schedule (`str`, defaults to `"linear"`):
+            The beta schedule, a mapping from a beta range to a sequence of betas for stepping the model. Choose from
+            `linear`, `scaled_linear`, or `squaredcos_cap_v2`.
+        clip_sample (`bool`, defaults to `True`):
+            Clip the predicted sample for numerical stability.
+        clip_sample_range (`float`, defaults to 1.0):
+            The maximum magnitude for sample clipping. Valid only when `clip_sample=True`.
+        set_alpha_to_one (`bool`, defaults to `True`):
+            Each diffusion step uses the alphas product value at that step and at the previous one. For the final step
+            there is no previous alpha. When this option is `True` the previous alpha product is fixed to `1`,
+            otherwise it uses the alpha value at step 0.
+        prediction_type (`str`, defaults to `epsilon`, *optional*):
+            Prediction type of the scheduler function; can be `epsilon` (predicts the noise of the diffusion process),
+            `sample` (directly predicts the noisy sample`) or `v_prediction` (see section 2.4 of [Imagen
+            Video](https://imagen.research.google/video/paper.pdf) paper).
+        thresholding (`bool`, defaults to `False`):
+            Whether to use the "dynamic thresholding" method. This is unsuitable for latent-space diffusion models such
+            as Stable Diffusion.
+        dynamic_thresholding_ratio (`float`, defaults to 0.995):
+            The ratio for the dynamic thresholding method. Valid only when `thresholding=True`.
+        sample_max_value (`float`, defaults to 1.0):
+            The threshold value for dynamic thresholding. Valid only when `thresholding=True`.
+        timestep_spacing (`str`, defaults to `"leading"`):
+            The way the timesteps should be scaled. Refer to Table 2 of the [Common Diffusion Noise Schedules and
+            Sample Steps are Flawed](https://huggingface.co/papers/2305.08891) for more information.
+        steps_offset (`int`, defaults to 0):
+            An offset added to the inference steps. You can use a combination of `offset=1` and
+            `set_alpha_to_one=False` to make the last step use step 0 for the previous alpha product like in Stable
+            Diffusion.
+        rescale_betas_zero_snr (`bool`, defaults to `False`):
+            Whether to rescale the betas to have zero terminal SNR. This enables the model to generate very bright and
+            dark samples instead of limiting it to samples with medium brightness. Loosely related to
+            [`--offset_noise`](https://github.com/huggingface/diffusers/blob/74fd735eb073eb1d774b1ab4154a0876eb82f055/examples/dreambooth/train_dreambooth.py#L506).
+        denoising_step_size (`int`, defaults to 250):
+            The denoising step size parameter from the UFOGen paper. The number of steps used for training is roughly
+            `math.ceil(num_train_timesteps / denoising_step_size)`.
+    """
+
+    order = 1
+
+    @register_to_config
+    def __init__(
+        self,
+        num_train_timesteps: int = 1000,
+        beta_start: float = 0.0001,
+        beta_end: float = 0.02,
+        beta_schedule: str = "linear",
+        trained_betas: Optional[Union[np.ndarray, List[float]]] = None,
+        clip_sample: bool = True,
+        set_alpha_to_one: bool = True,
+        prediction_type: str = "epsilon",
+        thresholding: bool = False,
+        dynamic_thresholding_ratio: float = 0.995,
+        clip_sample_range: float = 1.0,
+        sample_max_value: float = 1.0,
+        timestep_spacing: str = "leading",
+        steps_offset: int = 0,
+        rescale_betas_zero_snr: bool = False,
+        denoising_step_size: int = 250,
+    ):
+        if trained_betas is not None:
+            self.betas = torch.tensor(trained_betas, dtype=torch.float32)
+        elif beta_schedule == "linear":
+            self.betas = torch.linspace(beta_start, beta_end, num_train_timesteps, dtype=torch.float32)
+        elif beta_schedule == "scaled_linear":
+            # this schedule is very specific to the latent diffusion model.
+            self.betas = torch.linspace(beta_start**0.5, beta_end**0.5, num_train_timesteps, dtype=torch.float32) ** 2
+        elif beta_schedule == "squaredcos_cap_v2":
+            # Glide cosine schedule
+            self.betas = betas_for_alpha_bar(num_train_timesteps)
+        elif beta_schedule == "sigmoid":
+            # GeoDiff sigmoid schedule
+            betas = torch.linspace(-6, 6, num_train_timesteps)
+            self.betas = torch.sigmoid(betas) * (beta_end - beta_start) + beta_start
+        else:
+            raise NotImplementedError(f"{beta_schedule} does is not implemented for {self.__class__}")
+
+        # Rescale for zero SNR
+        if rescale_betas_zero_snr:
+            self.betas = rescale_zero_terminal_snr(self.betas)
+
+        self.alphas = 1.0 - self.betas
+        self.alphas_cumprod = torch.cumprod(self.alphas, dim=0)
+
+        # For the final step, there is no previous alphas_cumprod because we are already at 0
+        # `set_alpha_to_one` decides whether we set this parameter simply to one or
+        # whether we use the final alpha of the "non-previous" one.
+        self.final_alpha_cumprod = torch.tensor(1.0) if set_alpha_to_one else self.alphas_cumprod[0]
+
+        # standard deviation of the initial noise distribution
+        self.init_noise_sigma = 1.0
+
+        # setable values
+        self.custom_timesteps = False
+        self.num_inference_steps = None
+        self.timesteps = torch.from_numpy(np.arange(0, num_train_timesteps)[::-1].copy())
+
+    def scale_model_input(self, sample: torch.FloatTensor, timestep: Optional[int] = None) -> torch.FloatTensor:
+        """
+        Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
+        current timestep.
+
+        Args:
+            sample (`torch.FloatTensor`):
+                The input sample.
+            timestep (`int`, *optional*):
+                The current timestep in the diffusion chain.
+
+        Returns:
+            `torch.FloatTensor`:
+                A scaled input sample.
+        """
+        return sample
+
+    def set_timesteps(
+        self,
+        num_inference_steps: Optional[int] = None,
+        device: Union[str, torch.device] = None,
+        timesteps: Optional[List[int]] = None,
+    ):
+        """
+        Sets the discrete timesteps used for the diffusion chain (to be run before inference).
+
+        Args:
+            num_inference_steps (`int`):
+                The number of diffusion steps used when generating samples with a pre-trained model. If used,
+                `timesteps` must be `None`.
+            device (`str` or `torch.device`, *optional*):
+                The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
+            timesteps (`List[int]`, *optional*):
+                Custom timesteps used to support arbitrary spacing between timesteps. If `None`, then the default
+                timestep spacing strategy of equal spacing between timesteps is used. If `timesteps` is passed,
+                `num_inference_steps` must be `None`.
+
+        """
+        if num_inference_steps is not None and timesteps is not None:
+            raise ValueError("Can only pass one of `num_inference_steps` or `custom_timesteps`.")
+
+        if timesteps is not None:
+            for i in range(1, len(timesteps)):
+                if timesteps[i] >= timesteps[i - 1]:
+                    raise ValueError("`custom_timesteps` must be in descending order.")
+
+            if timesteps[0] >= self.config.num_train_timesteps:
+                raise ValueError(
+                    f"`timesteps` must start before `self.config.train_timesteps`:"
+                    f" {self.config.num_train_timesteps}."
+                )
+
+            timesteps = np.array(timesteps, dtype=np.int64)
+            self.custom_timesteps = True
+        else:
+            if num_inference_steps > self.config.num_train_timesteps:
+                raise ValueError(
+                    f"`num_inference_steps`: {num_inference_steps} cannot be larger than `self.config.train_timesteps`:"
+                    f" {self.config.num_train_timesteps} as the unet model trained with this scheduler can only handle"
+                    f" maximal {self.config.num_train_timesteps} timesteps."
+                )
+
+            self.num_inference_steps = num_inference_steps
+            self.custom_timesteps = False
+
+            # TODO: For now, handle special case when num_inference_steps == 1 separately
+            if num_inference_steps == 1:
+                # Set the timestep schedule to num_train_timesteps - 1 rather than 0
+                # (that is, the one-step timestep schedule is always trailing rather than leading or linspace)
+                timesteps = np.array([self.config.num_train_timesteps - 1], dtype=np.int64)
+            else:
+                # TODO: For now, retain the DDPM timestep spacing logic
+                # "linspace", "leading", "trailing" corresponds to annotation of Table 2. of https://arxiv.org/abs/2305.08891
+                if self.config.timestep_spacing == "linspace":
+                    timesteps = (
+                        np.linspace(0, self.config.num_train_timesteps - 1, num_inference_steps)
+                        .round()[::-1]
+                        .copy()
+                        .astype(np.int64)
+                    )
+                elif self.config.timestep_spacing == "leading":
+                    step_ratio = self.config.num_train_timesteps // self.num_inference_steps
+                    # creates integer timesteps by multiplying by ratio
+                    # casting to int to avoid issues when num_inference_step is power of 3
+                    timesteps = (np.arange(0, num_inference_steps) * step_ratio).round()[::-1].copy().astype(np.int64)
+                    timesteps += self.config.steps_offset
+                elif self.config.timestep_spacing == "trailing":
+                    step_ratio = self.config.num_train_timesteps / self.num_inference_steps
+                    # creates integer timesteps by multiplying by ratio
+                    # casting to int to avoid issues when num_inference_step is power of 3
+                    timesteps = np.round(np.arange(self.config.num_train_timesteps, 0, -step_ratio)).astype(np.int64)
+                    timesteps -= 1
+                else:
+                    raise ValueError(
+                        f"{self.config.timestep_spacing} is not supported. Please make sure to choose one of 'linspace', 'leading' or 'trailing'."
+                    )
+
+        self.timesteps = torch.from_numpy(timesteps).to(device)
+
+    # Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler._threshold_sample
+    def _threshold_sample(self, sample: torch.FloatTensor) -> torch.FloatTensor:
+        """
+        "Dynamic thresholding: At each sampling step we set s to a certain percentile absolute pixel value in xt0 (the
+        prediction of x_0 at timestep t), and if s > 1, then we threshold xt0 to the range [-s, s] and then divide by
+        s. Dynamic thresholding pushes saturated pixels (those near -1 and 1) inwards, thereby actively preventing
+        pixels from saturation at each step. We find that dynamic thresholding results in significantly better
+        photorealism as well as better image-text alignment, especially when using very large guidance weights."
+
+        https://arxiv.org/abs/2205.11487
+        """
+        dtype = sample.dtype
+        batch_size, channels, *remaining_dims = sample.shape
+
+        if dtype not in (torch.float32, torch.float64):
+            sample = sample.float()  # upcast for quantile calculation, and clamp not implemented for cpu half
+
+        # Flatten sample for doing quantile calculation along each image
+        sample = sample.reshape(batch_size, channels * np.prod(remaining_dims))
+
+        abs_sample = sample.abs()  # "a certain percentile absolute pixel value"
+
+        s = torch.quantile(abs_sample, self.config.dynamic_thresholding_ratio, dim=1)
+        s = torch.clamp(
+            s, min=1, max=self.config.sample_max_value
+        )  # When clamped to min=1, equivalent to standard clipping to [-1, 1]
+        s = s.unsqueeze(1)  # (batch_size, 1) because clamp will broadcast along dim=0
+        sample = torch.clamp(sample, -s, s) / s  # "we threshold xt0 to the range [-s, s] and then divide by s"
+
+        sample = sample.reshape(batch_size, channels, *remaining_dims)
+        sample = sample.to(dtype)
+
+        return sample
+
+    def step(
+        self,
+        model_output: torch.FloatTensor,
+        timestep: int,
+        sample: torch.FloatTensor,
+        generator: Optional[torch.Generator] = None,
+        return_dict: bool = True,
+    ) -> Union[UFOGenSchedulerOutput, Tuple]:
+        """
+        Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
+        process from the learned model outputs (most often the predicted noise).
+
+        Args:
+            model_output (`torch.FloatTensor`):
+                The direct output from learned diffusion model.
+            timestep (`float`):
+                The current discrete timestep in the diffusion chain.
+            sample (`torch.FloatTensor`):
+                A current instance of a sample created by the diffusion process.
+            generator (`torch.Generator`, *optional*):
+                A random number generator.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~schedulers.scheduling_ufogen.UFOGenSchedulerOutput`] or `tuple`.
+
+        Returns:
+            [`~schedulers.scheduling_ddpm.UFOGenSchedulerOutput`] or `tuple`:
+                If return_dict is `True`, [`~schedulers.scheduling_ufogen.UFOGenSchedulerOutput`] is returned, otherwise a
+                tuple is returned where the first element is the sample tensor.
+
+        """
+        # 0. Resolve timesteps
+        t = timestep
+        prev_t = self.previous_timestep(t)
+
+        # 1. compute alphas, betas
+        alpha_prod_t = self.alphas_cumprod[t]
+        alpha_prod_t_prev = self.alphas_cumprod[prev_t] if prev_t >= 0 else self.final_alpha_cumprod
+        beta_prod_t = 1 - alpha_prod_t
+        # beta_prod_t_prev = 1 - alpha_prod_t_prev
+        # current_alpha_t = alpha_prod_t / alpha_prod_t_prev
+        # current_beta_t = 1 - current_alpha_t
+
+        # 2. compute predicted original sample from predicted noise also called
+        # "predicted x_0" of formula (15) from https://arxiv.org/pdf/2006.11239.pdf
+        if self.config.prediction_type == "epsilon":
+            pred_original_sample = (sample - beta_prod_t ** (0.5) * model_output) / alpha_prod_t ** (0.5)
+        elif self.config.prediction_type == "sample":
+            pred_original_sample = model_output
+        elif self.config.prediction_type == "v_prediction":
+            pred_original_sample = (alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output
+        else:
+            raise ValueError(
+                f"prediction_type given as {self.config.prediction_type} must be one of `epsilon`, `sample` or"
+                " `v_prediction`  for UFOGenScheduler."
+            )
+
+        # 3. Clip or threshold "predicted x_0"
+        if self.config.thresholding:
+            pred_original_sample = self._threshold_sample(pred_original_sample)
+        elif self.config.clip_sample:
+            pred_original_sample = pred_original_sample.clamp(
+                -self.config.clip_sample_range, self.config.clip_sample_range
+            )
+
+        # 4. Single-step or multi-step sampling
+        # Noise is not used on the final timestep of the timestep schedule.
+        # This also means that noise is not used for one-step sampling.
+        if t != self.timesteps[-1]:
+            # TODO: is this correct?
+            # Sample prev sample x_{t - 1} ~ q(x_{t - 1} | x_0 =  G(x_t, t))
+            device = model_output.device
+            noise = randn_tensor(model_output.shape, generator=generator, device=device, dtype=model_output.dtype)
+            sqrt_alpha_prod_t_prev = alpha_prod_t_prev**0.5
+            sqrt_one_minus_alpha_prod_t_prev = (1 - alpha_prod_t_prev) ** 0.5
+            pred_prev_sample = sqrt_alpha_prod_t_prev * pred_original_sample + sqrt_one_minus_alpha_prod_t_prev * noise
+        else:
+            # Simply return the pred_original_sample. If `prediction_type == "sample"`, this is equivalent to returning
+            # the output of the GAN generator U-Net on the initial noisy latents x_T ~ N(0, I).
+            pred_prev_sample = pred_original_sample
+
+        if not return_dict:
+            return (pred_prev_sample,)
+
+        return UFOGenSchedulerOutput(prev_sample=pred_prev_sample, pred_original_sample=pred_original_sample)
+
+    # Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.add_noise
+    def add_noise(
+        self,
+        original_samples: torch.FloatTensor,
+        noise: torch.FloatTensor,
+        timesteps: torch.IntTensor,
+    ) -> torch.FloatTensor:
+        # Make sure alphas_cumprod and timestep have same device and dtype as original_samples
+        alphas_cumprod = self.alphas_cumprod.to(device=original_samples.device, dtype=original_samples.dtype)
+        timesteps = timesteps.to(original_samples.device)
+
+        sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
+        sqrt_alpha_prod = sqrt_alpha_prod.flatten()
+        while len(sqrt_alpha_prod.shape) < len(original_samples.shape):
+            sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
+
+        sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
+        sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
+        while len(sqrt_one_minus_alpha_prod.shape) < len(original_samples.shape):
+            sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
+
+        noisy_samples = sqrt_alpha_prod * original_samples + sqrt_one_minus_alpha_prod * noise
+        return noisy_samples
+
+    # Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.get_velocity
+    def get_velocity(
+        self, sample: torch.FloatTensor, noise: torch.FloatTensor, timesteps: torch.IntTensor
+    ) -> torch.FloatTensor:
+        # Make sure alphas_cumprod and timestep have same device and dtype as sample
+        alphas_cumprod = self.alphas_cumprod.to(device=sample.device, dtype=sample.dtype)
+        timesteps = timesteps.to(sample.device)
+
+        sqrt_alpha_prod = alphas_cumprod[timesteps] ** 0.5
+        sqrt_alpha_prod = sqrt_alpha_prod.flatten()
+        while len(sqrt_alpha_prod.shape) < len(sample.shape):
+            sqrt_alpha_prod = sqrt_alpha_prod.unsqueeze(-1)
+
+        sqrt_one_minus_alpha_prod = (1 - alphas_cumprod[timesteps]) ** 0.5
+        sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.flatten()
+        while len(sqrt_one_minus_alpha_prod.shape) < len(sample.shape):
+            sqrt_one_minus_alpha_prod = sqrt_one_minus_alpha_prod.unsqueeze(-1)
+
+        velocity = sqrt_alpha_prod * noise - sqrt_one_minus_alpha_prod * sample
+        return velocity
+
+    def __len__(self):
+        return self.config.num_train_timesteps
+
+    # Copied from diffusers.schedulers.scheduling_ddpm.DDPMScheduler.previous_timestep
+    def previous_timestep(self, timestep):
+        if self.custom_timesteps:
+            index = (self.timesteps == timestep).nonzero(as_tuple=True)[0][0]
+            if index == self.timesteps.shape[0] - 1:
+                prev_t = torch.tensor(-1)
+            else:
+                prev_t = self.timesteps[index + 1]
+        else:
+            num_inference_steps = (
+                self.num_inference_steps if self.num_inference_steps else self.config.num_train_timesteps
+            )
+            prev_t = timestep - self.config.num_train_timesteps // num_inference_steps
+
+        return prev_t
diff --git a/src/diffusers/utils/dummy_pt_objects.py b/src/diffusers/utils/dummy_pt_objects.py
index 263bcaea5a8d..1ca02d918af7 100644
--- a/src/diffusers/utils/dummy_pt_objects.py
+++ b/src/diffusers/utils/dummy_pt_objects.py
@@ -1005,6 +1005,21 @@ def from_pretrained(cls, *args, **kwargs):
         requires_backends(cls, ["torch"])
 
 
+class UFOGenScheduler(metaclass=DummyObject):
+    _backends = ["torch"]
+
+    def __init__(self, *args, **kwargs):
+        requires_backends(self, ["torch"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch"])
+
+
 class UnCLIPScheduler(metaclass=DummyObject):
     _backends = ["torch"]
 
diff --git a/tests/pipelines/stable_diffusion/test_stable_diffusion.py b/tests/pipelines/stable_diffusion/test_stable_diffusion.py
index 28d0d07e6948..e89df5c9933e 100644
--- a/tests/pipelines/stable_diffusion/test_stable_diffusion.py
+++ b/tests/pipelines/stable_diffusion/test_stable_diffusion.py
@@ -35,6 +35,7 @@
     LMSDiscreteScheduler,
     PNDMScheduler,
     StableDiffusionPipeline,
+    UFOGenScheduler,
     UNet2DConditionModel,
     logging,
 )
@@ -242,6 +243,26 @@ def test_stable_diffusion_lcm_custom_timesteps(self):
 
         assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
 
+    def test_stable_diffusion_ufogen(self):
+        device = "cpu"  # ensure determinism for the device-dependent torch.Generator
+
+        components = self.get_dummy_components()
+        sd_pipe = StableDiffusionPipeline(**components)
+        sd_pipe.scheduler = UFOGenScheduler.from_config(sd_pipe.scheduler.config)
+        sd_pipe = sd_pipe.to(torch_device)
+        sd_pipe.set_progress_bar_config(disable=None)
+
+        inputs = self.get_dummy_inputs(device)
+        output = sd_pipe(**inputs)
+        image = output.images
+
+        image_slice = image[0, -3:, -3:, -1]
+
+        assert image.shape == (1, 64, 64, 3)
+        expected_slice = np.array([0.3260, 0.4523, 0.4684, 0.3544, 0.3981, 0.4635, 0.5140, 0.3425, 0.4062])
+
+        assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
+
     def test_stable_diffusion_prompt_embeds(self):
         components = self.get_dummy_components()
         sd_pipe = StableDiffusionPipeline(**components)
diff --git a/tests/schedulers/test_scheduler_ufogen.py b/tests/schedulers/test_scheduler_ufogen.py
new file mode 100644
index 000000000000..2fb8ac1ea639
--- /dev/null
+++ b/tests/schedulers/test_scheduler_ufogen.py
@@ -0,0 +1,182 @@
+import torch
+
+from diffusers import UFOGenScheduler
+
+from .test_schedulers import SchedulerCommonTest
+
+
+class UFOGenSchedulerTest(SchedulerCommonTest):
+    scheduler_classes = (UFOGenScheduler,)
+
+    def get_scheduler_config(self, **kwargs):
+        config = {
+            "num_train_timesteps": 1000,
+            "beta_start": 0.0001,
+            "beta_end": 0.02,
+            "beta_schedule": "linear",
+            "clip_sample": True,
+        }
+
+        config.update(**kwargs)
+        return config
+
+    def test_timesteps(self):
+        for num_train_timesteps, timestep in zip([1, 5, 100, 1000], [0, 0, 0, 0]):
+            self.check_over_configs(num_train_timesteps=num_train_timesteps, time_step=timestep)
+
+    def test_betas(self):
+        for beta_start, beta_end in zip([0.0001, 0.001, 0.01, 0.1], [0.002, 0.02, 0.2, 2]):
+            self.check_over_configs(beta_start=beta_start, beta_end=beta_end)
+
+    def test_schedules(self):
+        for schedule in ["linear", "squaredcos_cap_v2"]:
+            self.check_over_configs(beta_schedule=schedule)
+
+    def test_clip_sample(self):
+        for clip_sample in [True, False]:
+            self.check_over_configs(clip_sample=clip_sample)
+
+    def test_thresholding(self):
+        self.check_over_configs(thresholding=False)
+        for threshold in [0.5, 1.0, 2.0]:
+            for prediction_type in ["epsilon", "sample", "v_prediction"]:
+                self.check_over_configs(
+                    thresholding=True,
+                    prediction_type=prediction_type,
+                    sample_max_value=threshold,
+                )
+
+    def test_prediction_type(self):
+        for prediction_type in ["epsilon", "sample", "v_prediction"]:
+            self.check_over_configs(prediction_type=prediction_type)
+
+    def test_time_indices(self):
+        for t in [0, 500, 999]:
+            self.check_over_forward(time_step=t)
+
+    def full_loop(self, num_inference_steps=10, **config):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config(**config)
+        scheduler = scheduler_class(**scheduler_config)
+
+        model = self.dummy_model()
+        sample = self.dummy_sample_deter
+        generator = torch.manual_seed(0)
+
+        scheduler.set_timesteps(num_inference_steps)
+
+        for t in scheduler.timesteps:
+            residual = model(sample, t)
+            sample = scheduler.step(residual, t, sample, generator=generator).prev_sample
+
+        return sample
+
+    def test_full_loop_no_noise(self):
+        sample = self.full_loop()
+
+        result_sum = torch.sum(torch.abs(sample))
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_sum.item() - 201.3429) < 1e-2
+        assert abs(result_mean.item() - 0.2622) < 1e-3
+
+    def test_full_loop_no_noise_onestep(self):
+        sample = self.full_loop(num_inference_steps=1)
+
+        result_sum = torch.sum(torch.abs(sample))
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_sum.item() - 61.5819) < 1e-2
+        assert abs(result_mean.item() - 0.0802) < 1e-3
+
+    def test_full_loop_with_v_prediction(self):
+        sample = self.full_loop(prediction_type="v_prediction")
+
+        result_sum = torch.sum(torch.abs(sample))
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_sum.item() - 141.1963) < 1e-2
+        assert abs(result_mean.item() - 0.1838) < 1e-3
+
+    def test_full_loop_with_noise(self, num_inference_steps=10):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config()
+        scheduler = scheduler_class(**scheduler_config)
+
+        model = self.dummy_model()
+        sample = self.dummy_sample_deter
+        generator = torch.manual_seed(0)
+
+        t_start = num_inference_steps - 2
+        scheduler.set_timesteps(num_inference_steps)
+
+        # add noise
+        noise = self.dummy_noise_deter
+        timesteps = scheduler.timesteps[t_start * scheduler.order :]
+        sample = scheduler.add_noise(sample, noise, timesteps[:1])
+
+        for t in timesteps:
+            residual = model(sample, t)
+            sample = scheduler.step(residual, t, sample, generator=generator).prev_sample
+
+        result_sum = torch.sum(torch.abs(sample))
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_sum.item() - 350.1980) < 1e-2, f" expected result sum 387.9466, but get {result_sum}"
+        assert abs(result_mean.item() - 0.4560) < 1e-3, f" expected result mean 0.5051, but get {result_mean}"
+
+    def test_custom_timesteps(self):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config()
+        scheduler = scheduler_class(**scheduler_config)
+
+        timesteps = [100, 87, 50, 1, 0]
+
+        scheduler.set_timesteps(timesteps=timesteps)
+
+        scheduler_timesteps = scheduler.timesteps
+
+        for i, timestep in enumerate(scheduler_timesteps):
+            if i == len(timesteps) - 1:
+                expected_prev_t = -1
+            else:
+                expected_prev_t = timesteps[i + 1]
+
+            prev_t = scheduler.previous_timestep(timestep)
+            prev_t = prev_t.item()
+
+            self.assertEqual(prev_t, expected_prev_t)
+
+    def test_custom_timesteps_increasing_order(self):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config()
+        scheduler = scheduler_class(**scheduler_config)
+
+        timesteps = [100, 87, 50, 51, 0]
+
+        with self.assertRaises(ValueError, msg="`custom_timesteps` must be in descending order."):
+            scheduler.set_timesteps(timesteps=timesteps)
+
+    def test_custom_timesteps_passing_both_num_inference_steps_and_timesteps(self):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config()
+        scheduler = scheduler_class(**scheduler_config)
+
+        timesteps = [100, 87, 50, 1, 0]
+        num_inference_steps = len(timesteps)
+
+        with self.assertRaises(ValueError, msg="Can only pass one of `num_inference_steps` or `custom_timesteps`."):
+            scheduler.set_timesteps(num_inference_steps=num_inference_steps, timesteps=timesteps)
+
+    def test_custom_timesteps_too_large(self):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config()
+        scheduler = scheduler_class(**scheduler_config)
+
+        timesteps = [scheduler.config.num_train_timesteps]
+
+        with self.assertRaises(
+            ValueError,
+            msg="`timesteps` must start before `self.config.train_timesteps`: {scheduler.config.num_train_timesteps}}",
+        ):
+            scheduler.set_timesteps(timesteps=timesteps)