The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies like tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue engineered constructs, as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims to determine how collagen vs. fibrin hydrogels affect the biological, structural and mechanical properties of tissue engineered constructs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared to their collagen-based counterparts up to 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared to collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue engineered tendon/ligament repair.