Injectable dermal fillers have attracted significant attention for tissue augmentation. However, conventional particulate fillers suffer from high injection force, risk of vascular occlusion, and limited moldability. Here, we report a photo-responsive liquid dermal filler based on photocrosslinkable hyaluronic acid (HA) that enables in situ hydrogel formation upon short, non-toxic visible light exposure. This HA photofiller exhibits low viscosity, allowing facile injection with a low force (<8 N) through a 34-gauge needle. The mechanical properties of the cured hydrogel can be precisely tuned by adjusting polymer concentration. For enhanced regenerative potential, a growth factor for collagen biosynthesis was incorporated, resulting in increased COL1A1 expression in dermal fibroblasts. In vivo mouse studies demonstrated excellent stability of HA photofiller, with over 90% volume retention at 28 days, minimal inflammatory response, and enhanced collagen deposition. Thus, this photo-responsive HA photofiller represents a promising dual-action dermal filler that combines on-demand gelation with regenerative functionality.