Collagen is one of the most widely used biomaterials for tissue engineering and regenerative medicine. Fish collagen peptides (FCP) have been used as a dietary supplement, but their effects on the cellular function are still poorly understood. The objective of this study was to investigate the effects of FCP on collagen synthesis, quality and mineralization using an osteoblastic MC3T3-E1 cell culture system. Cells treated with FCP significantly upregulated the gene expression of several collagen modifying enzymes and more collagen was deposited in the cultures. Collagen in the treated group showed a greater extent of lysine hydroxylation, higher levels of hydroxylysine-aldehyde derived cross-links and accelerated cross-link maturation compared with the untreated group. Furthermore, the treated group showed accelerated matrix mineralization. These results indicate that FCP exerts a positive effect on osteoblastic cells in terms of collagen synthesis, quality and mineralization, thereby suggesting the potential utility of FCP for bone tissue engineering.