γδ T cells occupy a unique immunological niche, bridging innate and adaptive immune function within a single cellular compartment. The lineage-defining γδ T cell receptor undergoes VDJ recombination in the thymus, but can recognize self-ligands, bind to ligands using germline encoded residues, and recognize antigens outside the context of MHC molecules. This dissertation addresses the still unknown role of the γδ TCR in postnatal thymic Vδ1+ T cell development, and shows that variation in the constant region of the γδ TCR durably influences thymic programming and peripheral function of γδ T cells. These roles for the γδ TCR in T cell function are distinct from known programs of αβ T cell development and function, and provide novel insights into the role of the γδ TCR in programming T cells in health and disease.