The immune checkpoint receptor PD-1 on T follicular helper (Tfh) cells promotes Tfh:B cell interactions and appropriate positioning within tissues. Here, we examined the impact of regulation of PD-1 expression by the genomic organizer SATB1 on Tfh cell differentiation. Vaccination of CD4CreSatb1f/f mice enriched for antigen-specific Tfh cells, and TGF-β-mediated repression of SATB1 enhanced Tfh differentiation of human T cells. Mechanistically, high Icos expression in Satb1−/− CD4+ T cells promoted Tfh cell differentiation by preventing T follicular regulatory cell skewing and resulted in increased isotype-switched B cell responses in vivo. Ovarian tumors in CD4CreSatb1f/f mice accumulated tumor antigen-specific, LIGHT+CXCL13+IL-21+ Tfh cells and tertiary lymphoid structures (TLS). TLS formation decreased tumor growth in a CD4+ T cell and CXCL13-dependent manner. The transfer of Tfh cells, but not naive CD4+ T cells, induced TLS at tumor beds and decreased tumor growth. Thus, TGF-β-mediated silencing of Satb1 licenses Tfh cell differentiation, providing insight into the genesis of TLS within tumors. Display omitted •Satb1−/− CD4+ T cells show heightened antigen-specific Tfh cell differentiation•SATB1-mediated suppression of Icos expression is required for Tfr cell differentiation•CD4CreSatb1f/f mice spontaneously develop intra-tumoral tertiary lymphoid structures•Tfh cell transfer elicits intra-tumoral TLS assembly and reduces tumor growth Tertiary lymphoid structures (TLS) are associated with improved outcomes for cancer patients. Chaurio et al. demonstrate that TGF-β-mediated regulation of the genomic organizer Satb1 governs the differentiation of T follicular helper (Tfh) cells and T follicular regulatory cells. Loss of Satb1 promotes Icos expression and thereby Tfh cell differentiation, resulting in the assembly of intra-tumoral TLS.