UniRef is a unified model for image and video object segmentation. It supports multiple tasks such as Semantic Reference Image Segmentation (RIS), Few-Shot Segmentation (FSS), Semantic Reference Video Object Segmentation (RVOS), and Video Object Segmentation (VOS). The core of UniRef is the UniFusion module, which can efficiently inject various reference information into the basic network. UniRef can be used as a plugin component for basic models like SAM. UniRef provides pre-trained models on multiple benchmark datasets and also offers open-source code for research purposes.