Proper metabolic activities facilitate T cell expansion and antitumor function; however, the mechanisms underlying disruption of the T cell metabolic program and function in the tumor microenvironment (TME) remain elusive. Here, we show a zinc finger protein 91-governed (ZFP91-governed) mechanism that disrupts the metabolic pathway and antitumor activity of tumor-infiltrating T cells. Single-cell RNA-Seq revealed that impairments in T cell proliferation and activation correlated with ZFP91 in tissue samples from patients with colorectal cancer. T cell-specific deletion of Zfp91 in mice led to enhanced T cell proliferation and potentiated T cell antitumor function. Loss of ZFP91 increased mammalian target of rapamycin complex 1 (mTORC1) activity to drive T cell glycolysis. Mechanistically, T cell antigen receptor-dependent (TCR-dependent) ZFP91 cytosolic translocation promoted protein phosphatase 2A (PP2A) complex assembly, thereby restricting mTORC1-mediated metabolic reprogramming. Our results demonstrate that ZFP91 perturbs T cell metabolic and functional states in the TME and suggest that targeting ZFP91 may improve the efficacy of cancer immunotherapy.