Cell encapsulation in biodegradable hydrogels is a promising approach for tissue engineering, offering advantages such as ease of handling, a tissue-like environment for cell growth, and in vivo formation. Hydrogel properties like swelling, mechanical strength, degradation, and diffusion are closely linked to their crosslinked structure, which is influenced by processing conditions. Degradation can be controlled by incorporating hydrolytically or enzymatically labile segments or using natural biopolymers. However, the number of suitable chemistries is limited due to the presence of cells during gelation. This review discusses important considerations for designing biodegradable hydrogels for cell encapsulation and highlights recent advances in material design and their applications in tissue engineering. Hydrogels are attractive for tissue engineering due to their water-swelling, water-insoluble, crosslinked networks with high water content and tissue-like elastic properties. Biocompatible hydrogels formed from macromolecular precursors and mild gelation conditions are used to encapsulate cells in 3D scaffolds. Early work used naturally forming and biodegradable hydrogels from collagen, fibrin, or alginate, but control over gelation, mechanical properties, and degradation was challenging. Tissue engineering aims to create living tissues with structural and biochemical similarity to native tissues. Designing suitable hydrogels for cell encapsulation requires considering mild gelation processes, cell-friendly materials, and degradation that follows tissue growth. Recent strategies focus on synthetic hydrogels for greater control, while natural chemistries are added to create bioactive hydrogels. Hydrogels are formed through various gelation mechanisms, including radical chain polymerization, chemical crosslinking, and mixed-mode polymerizations. Each mechanism has unique precursors and degradation mechanisms, with considerations for cytocompatibility and degradation kinetics. Hydrogel structure and chemistry influence macroscopic properties like swelling, mechanical strength, and degradation. The mesh size controls diffusion of nutrients and ECM molecules, affecting tissue development. Hydrophilic polymers like PEG resist protein adsorption and cell adhesion, while some cells require adhesion sites for survival. Hydrogel degradation is influenced by degradable linkages, crosslinking density, and the in vivo environment. Hydrolytically or enzymatically labile linkages are broken during degradation, with degradation profiles controlled by linker chemistry and structure. Hydrogels used in cell encapsulation include naturally forming hydrogels like collagen, fibrin, and alginate, and synthetic hydrogels. Synthetic hydrogels offer greater control over gelation and degradation, and can incorporate biological signals. Recent advances include DNA-based gels, protein-based gels, and synthetic ECM analogs. These hydrogels have been used for various tissue engineering applications, including cartilage, bone, and neural tissue regeneration. Practical considerations include scalability, FDA approval, and clinical acceptance. Overall, biodegradable hydrogels are a promising approach for tissue engineeringCell encapsulation in biodegradable hydrogels is a promising approach for tissue engineering, offering advantages such as ease of handling, a tissue-like environment for cell growth, and in vivo formation. Hydrogel properties like swelling, mechanical strength, degradation, and diffusion are closely linked to their crosslinked structure, which is influenced by processing conditions. Degradation can be controlled by incorporating hydrolytically or enzymatically labile segments or using natural biopolymers. However, the number of suitable chemistries is limited due to the presence of cells during gelation. This review discusses important considerations for designing biodegradable hydrogels for cell encapsulation and highlights recent advances in material design and their applications in tissue engineering. Hydrogels are attractive for tissue engineering due to their water-swelling, water-insoluble, crosslinked networks with high water content and tissue-like elastic properties. Biocompatible hydrogels formed from macromolecular precursors and mild gelation conditions are used to encapsulate cells in 3D scaffolds. Early work used naturally forming and biodegradable hydrogels from collagen, fibrin, or alginate, but control over gelation, mechanical properties, and degradation was challenging. Tissue engineering aims to create living tissues with structural and biochemical similarity to native tissues. Designing suitable hydrogels for cell encapsulation requires considering mild gelation processes, cell-friendly materials, and degradation that follows tissue growth. Recent strategies focus on synthetic hydrogels for greater control, while natural chemistries are added to create bioactive hydrogels. Hydrogels are formed through various gelation mechanisms, including radical chain polymerization, chemical crosslinking, and mixed-mode polymerizations. Each mechanism has unique precursors and degradation mechanisms, with considerations for cytocompatibility and degradation kinetics. Hydrogel structure and chemistry influence macroscopic properties like swelling, mechanical strength, and degradation. The mesh size controls diffusion of nutrients and ECM molecules, affecting tissue development. Hydrophilic polymers like PEG resist protein adsorption and cell adhesion, while some cells require adhesion sites for survival. Hydrogel degradation is influenced by degradable linkages, crosslinking density, and the in vivo environment. Hydrolytically or enzymatically labile linkages are broken during degradation, with degradation profiles controlled by linker chemistry and structure. Hydrogels used in cell encapsulation include naturally forming hydrogels like collagen, fibrin, and alginate, and synthetic hydrogels. Synthetic hydrogels offer greater control over gelation and degradation, and can incorporate biological signals. Recent advances include DNA-based gels, protein-based gels, and synthetic ECM analogs. These hydrogels have been used for various tissue engineering applications, including cartilage, bone, and neural tissue regeneration. Practical considerations include scalability, FDA approval, and clinical acceptance. Overall, biodegradable hydrogels are a promising approach for tissue engineering