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Fish collagen is known to have moisture-retaining and antioxidant ability. We examined the protective activity of fish collagen hydrolysates derived from Nile tilapia (Oreochromis niloticus) skin, which were dispersed in aqueous phase at the concentration of 72g/L (Fish Collagen), against UVA-irradiation in three-dimensional (3D) human skin tissue models. Fish Collagen was administered subcutaneously at doses of 2.5–10% in the medium of 3D-skin models and incubated for 72 h. Fish Collagen was demonstrated by its autofluorescence to permeate upwardly into the epidermis. Then the surfaces of 3D-skin models were exposed to 15-time repetition of UVA by 4 J/cm 2 for 4 days (sum: 60 J/cm 2 ). UVA-caused epidermal surface roughness and disruption of vertical dermal layer were detected by scanning electron microscopy. DNA strand cleavages and pycnosis/karyorrhexis indicative of apoptosis were observed in vertical cross-sections of UVA-irradiated 3D-skin models visualized with Hoechst 33342 stain. However, these skin damages were appreciably repressed by Fish Collagen dose-dependently, and 10% Fish Collagen served a sufficiently protective function for 3D-skin models against UVA. These suggest that Fish Collagen was permeated upwardly into the 3D-skin models, which resulted in strengthened collagen fibrils and preserved keratinocytes against UVA.