Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel derived from modified natural extracellular matrix (ECM) components, offering a cell-responsive platform for microengineered tissues and microfluidic devices. This study demonstrates that GelMA can be used to create cell-laden microtissues and microfluidic channels with high pattern fidelity and tunable mechanical and swelling properties. The degree of methacrylation was found to significantly affect the mechanical stiffness and swelling behavior of GelMA, with higher methacrylation leading to increased stiffness and lower swelling. GelMA exhibited excellent cell adhesion, proliferation, elongation, and migration properties, making it suitable for creating complex, cell-responsive microtissues such as endothelialized microvasculature. The hydrogel can be patterned to create perfusable microfluidic channels, enabling the seeding of endothelial cells for engineered tissues. GelMA also showed good cell viability and encapsulation properties, with encapsulated cells demonstrating elongation, migration, and organization. The study highlights the potential of GelMA as a versatile material for tissue engineering applications, offering a balance between mechanical stability, cell responsiveness, and tunable properties. The results suggest that GelMA could be used in a wide range of microscale applications where other hydrogels are not well suited, such as for creating endothelial-lined vasculature within engineered tissues.Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel derived from modified natural extracellular matrix (ECM) components, offering a cell-responsive platform for microengineered tissues and microfluidic devices. This study demonstrates that GelMA can be used to create cell-laden microtissues and microfluidic channels with high pattern fidelity and tunable mechanical and swelling properties. The degree of methacrylation was found to significantly affect the mechanical stiffness and swelling behavior of GelMA, with higher methacrylation leading to increased stiffness and lower swelling. GelMA exhibited excellent cell adhesion, proliferation, elongation, and migration properties, making it suitable for creating complex, cell-responsive microtissues such as endothelialized microvasculature. The hydrogel can be patterned to create perfusable microfluidic channels, enabling the seeding of endothelial cells for engineered tissues. GelMA also showed good cell viability and encapsulation properties, with encapsulated cells demonstrating elongation, migration, and organization. The study highlights the potential of GelMA as a versatile material for tissue engineering applications, offering a balance between mechanical stability, cell responsiveness, and tunable properties. The results suggest that GelMA could be used in a wide range of microscale applications where other hydrogels are not well suited, such as for creating endothelial-lined vasculature within engineered tissues.