The immune system must distinguish pathogens from innocuous dietary antigens, but the precise mechanisms and cellular actors remain unclear. Here, we demonstrate that RORγt-lineage APCs are required for oral tolerance. Using lineage tracing and single-cell sequencing, we show these APCs consist of three principal populations: type 3 innate lymphoid cells (ILC3s), RORγt-lineage dendritic cells, and cells expressing Aire called RORγt eTACs (R-eTACs)-also known as Janus or Thetis cells. We show that R-eTACs, but not ILC3s, are required for oral tolerance induction. We find R-eTACs are of probable myeloid origin and uniquely express integrin β8 (Itgb8). Both MHCII and Itgb8 expression in RORγt-lineage cells are necessary to induce food-specific regulatory T cells. Mice lacking R-eTACs or with deletion of MHCII or Itgb8 in the RORγt lineage fail to generate Tregs and instead develop a T-follicular helper response with elevated antigen-specific antibodies. These findings establish R-eTACs as critical mediators of oral tolerance and suggest novel cellular targets to modulate immune tolerance.