Traditional bone-repair materials are limited by poor growth-factor stability, imprecise release kinetics, and insufficient adaptation to pathological microenvironments. Functionalized photocrosslinkable hydrogels provide a tunable platform for local delivery and for regulating immune, metabolic, redox, and angiogenic responses. This review summarizes recent advances in these hydrogels for bone regeneration, with emphasis on microenvironment reprogramming, stimulus-responsive release, biomimetic design, and coordinated repair mechanisms. Current studies show that physical, chemical, and multistimulus-responsive systems can improve the spatial and temporal control of bioactive cargo, while material composition, structure, and interfacial properties influence macrophage polarization, stem-cell osteogenesis, and vascular-bone coupling. Most evidence, however, remains preclinical. Reproducible manufacturing, long-term biosafety, regulatory classification, and validation in clinically relevant models remain major barriers to translation. Addressing these issues may support the development of functionalized hydrogels from passive carriers into adaptive platforms for bone-defect repair.