The transcription factors Bcl6 and Blimp1 have opposing roles in the development of the follicular helper T (TFH) cells: Bcl6 promotes and Blimp1 inhibits TFH cell differentiation. Similarly, Bcl6 activates, while Blimp1 represses, expression of the TFH cell marker PD-1. However, Bcl6 and Blimp1 repress each other’s expression, complicating the interpretation of the regulatory network. Here we sought to clarify the extent to which Bcl6 and Blimp1 independently control TFH cell differentiation by generating mice with T cell specific deletion of both Bcl6 and Blimp1 (double conditional KO [dcKO] mice). Our data indicate that Blimp1 does not control TFH cell differentiation independently of Bcl6. However, a population of T follicular regulatory (TFR) cells developed independently of Bcl6 in dcKO mice. We next analyzed regulation of IL-10 and PD-1, two genes controlled by both Bcl6 and Blimp1, and observed that Bcl6 regulates both genes independently of Blimp1. We found Bcl6 positively regulates PD-1 expression by inhibiting the ability of Tbet/Tbx21 to repress Pdcd1 transcription. Our data show a novel mechanism for positive control of gene expression by Bcl6, and illuminate how Bcl6 and Blimp1 control TFH cell differentiation.