Thermo-responsive hydrogels (thermogels), known for their sol-gel transition capabilities, have garnered significant interest for biomedical applications over recent decades. However, conventional thermogels are hindered by intrinsic physicochemical and functional limitations that impede their broader utility. This study introduces methacryl glycol chitosan (MGC) as a novel thermogel, offering enhanced functionality and addressing these limitations. MGCs, synthesized through N-methacrylation of glycol chitosan, exhibit tunable thermogelling and photo-crosslinking behaviors. The thermo-reversible sol-gel transition of MGCs occurs within a 21–54 °C range, adjustable by polymer concentration and methacryl substitution degree. Photo-crosslinking using UV light further enhances the mechanical properties of MGC thermogels, creating thermo-irreversible, chemically crosslinked hydrogels. MGCs show no cytotoxic effects and effectively support cell encapsulation. In vivo studies demonstrate stable crosslinking with minimal UV-induced skin damage. Due to their unique thermo-sensitivity, multi-functionality, and customizable properties, MGC thermogels are promising novel biomaterials for various biomedical applications, particularly injectable tissue engineering and cell encapsulation, thus overcoming the limitations of conventional thermogels.