Statement of Purpose: The osteotendinous junction links tendon to bone via a continuous fibrocartilaginous interface (enthesis) that reduces interfacial strain and decreases the risk of failure between highly elastic tendon and 100-fold stiffer bone.1 Osteotendinous injuries can take place via acute (e.g. overload) or degradative (e.g. aging) processes. Surgical interventions that mechanically fix the torn tendon to bone result in poor healing of the native enthesis and high re-failure rates.2 Functional reintegration of the torn tissues requires regeneration of the compliant fibrocartilaginous interface. Progress towards regenerating the tendon-to-bone enthesis is hampered by an inability for biomaterials to present spatially continuous interface zones or to overcome high levels of local strain that form at the interface between dissimilar tissues. We describe a triphasic biomaterial comprising osseous and tendinous collagen-GAG (CG) scaffold zones integrated via a compliant polyethylene glycol (PEG) hydrogel seam. We report tuning biomaterial properties by varying the gelation rate and stiffness of the hydrogel seam to control the topology of the interface and resultant mechanical properties and deformation under tensile load. The flanking CG zones promote region-specific osteogenic and tenogenic behavior in human mesenchymal stem cells (hMSCs)3, and the interfacial hydrogel seam grants a platform to explicitly address interface remodeling. Individually, these compartments address local cell response using tissue-relevant matrix structural cues, and together form a continuous scaffold that mimics the physical behavior of osteotendinous tissue.