Tendons can withstand large forces due to a highly aligned, dense collagen matrix. However, their low cellularity and relative inability to recruit reparative cells post-injury, as well as susceptibility to excessive scarring, results in loss of tendon structure and mechanical function. Type I collagen (Col1) is the primary collagen of healthy tendon and type III collagen (Col3) is a minor constituent that increases in response to injury. In other Col1-rich tissues such as skin and bone, Col3 directs reparative cell activities by regulating early cellular infiltration to promote healing, as well as collagen deposition, architecture and crosslink formation, supporting an early critical role of Col3 in wound healing, which has not been studied in tendon. While Col3 may orchestrate cellular activities and fate that are critical for an optimal reparative response post-injury at early stages in tendon, its persistent expression in the remodeling phase may compromise the desired healing response. Therefore, the overall objective of this study was to define the critical role of fibrillar collagens, Col3 and Col5, in modulating matrix maturation and healing potential throughout tendon healing. Overall, it is apparent that both fibrillar collagens studied play a role in tendon healing, through modulation of fibrillogenesis, matrix organization and engagement. While Col5 seems to be necessary for matrix integrity throughout the time course studied, Col3 seems to play a larger role in fibrillogenesis early on, as well as plays a large role in influencing cellular populations during the inflammatory phase. Further elucidating the mechanistic roles of fibrillar collagens in tendon healing will allow for potential modulation of matrix deposition post-injury to optimize the regenerative environment and result in better functional outcomes.