Human induced pluripotent stem cells (iPSCs) provide a potentially unlimited resource for cell therapies, but the derivation of mature cell types remains challenging. The histone methyltransferase EZH1 is a negative regulator of lymphoid potential during embryonic hematopoiesis. Here, we demonstrate that EZH1 repression facilitates in vitro differentiation and maturation of T cells from iPSCs. Coupling a stroma-free T cell differentiation system with EZH1-knockdown-mediated epigenetic reprogramming, we generated iPSC-derived T cells, termed EZ-T cells, which display a highly diverse T cell receptor (TCR) repertoire and mature molecular signatures similar to those of TCRαβ T cells from peripheral blood. Upon activation, EZ-T cells give rise to effector and memory T cell subsets. When transduced with chimeric antigen receptors (CARs), EZ-T cells exhibit potent antitumor activities in vitro and in xenograft models. Epigenetic remodeling via EZH1 repression allows efficient production of developmentally mature T cells from iPSCs for applications in adoptive cell therapy. Display omitted •Stroma-free differentiation of iPSCs into T cells expressing diverse TCRs•EZH1 repression generates mature EZ-T cells similar to peripheral blood αβ T cells•EZ-T cells can give rise to memory-like T cells upon activation•CAR EZ-T cells display enhanced antitumor activity in vitro and in vivo Jing et al. combine a stroma-free differentiation system with EZH1-repression-mediated epigenetic reprogramming to generate developmentally mature iPSC-derived CAR T cells with enhanced antitumor activities.