Carboxy-terminal domain small phosphatase like 2 (CTDSPL2), one of the haloacid dehalogenase phosphatases, is associated with several diseases including cancer. However, the role of CTDSPL2 and its regulatory mechanism in lung cancer remain unclear. Here, we aimed to explore the clinical implications, biological functions, and molecular mechanisms of CTDSPL2 in non-small cell lung cancer (NSCLC). CTDSPL2 was identified as a novel target of the tumor suppressor miR-193a-3p. CTDSPL2 expression was significantly elevated in NSCLC tissues. Database analysis showed that CTDSPL2 expression was negatively correlated with patient survival. Depletion of CTDSPL2 inhibited the proliferation, migration, and invasion of NSCLC cells, as well as tumor growth and metastasis in mouse models. Additionally, silencing of CTDSPL2 enhanced CD4 T cell infiltration into tumors. Moreover, CTDSPL2 interacted with JAK1 and positively regulated JAK1 expression. Subsequent experiments indicated that CTDSPL2 activated the PI3K/AKT signaling pathway through the upregulation of JAK1, thereby promoting the progression of NSCLC. In conclusion, CTDSPL2 may play an oncogenic role in NSCLC progression by activating PI3K/AKT signaling via JAK1. These findings may provide a potential target for the diagnosis and treatment of NSCLC.