Foxp 3+ retinoic acid-related orphan receptor (ROR)gt+ T cells have recently been characterized as an immunoregulatory population highly enriched in the colon lamina propria. However, their developmental origin and relationship to RORgt2 regulatory T and Th17 cells remain unclear. In this study, we use a fixed TCRb system to show that the TCR repertoire of the Foxp3+RORgt+ population is mostly distinct compared with other colonic T cell subsets. However, of these TCRs, a fraction is also found in the Th17 subset, suggesting that TCR repertoire overlap may contribute to the reported ability of Foxp3+RORgt+ cells to regulate Th17 immunity. Naive transgenic T cells expressing a Foxp3+RORgt+-restricted TCR first acquire a Foxp3+RORgt2 phenotype before coexpressing RORgt, suggesting that Foxp3+RORgt+ cell development can occur via an RORgt2 regulatory T cell intermediate.