Neuroinflammatory diseases such as multiple sclerosis are characterized by infiltration of lymphocytes into the central nervous system followed by demyelination and axonal degeneration. While evidence suggests that activated T lymphocytes induce neurotoxicity and impair function of neural stem cells, the effect of T cells on oligodendrocyte progenitor cells (OPCs) is still uncertain, partly due to the difficulty in obtaining human OPCs. Here we studied the effect of activated T cells on OPCs using OPCs derived from human hematopoietic stem cells or from human fetal brain. OPCs were exposed to supernatants (sups) from activated T cells. Cell proliferation was determined by EdU incorporation and CellQuanti‐Blue assays. Surprisingly, we found that sups from activated T cells induced OPC proliferation by regulating cell cycle progression. Vascular endothelial growth factor A (VEGF‐A) transcripts were increased in T cells after activation. Immunodepletion of VEGF‐A from activated T cell sups significantly attenuated its effect on OPC proliferation. Furthermore, VEGF receptor 2 (VEGFR2) was expressed on OPCs and its inhibition also attenuated activated T cell‐induced OPC proliferation. Thus, activated T cells have a trophic role by promoting OPC proliferation via the VEGFR2 pathway. Main Points Activated T cells induce OPC proliferation. Activation of T cells produce VEGF‐A Depletion of VEGF‐A attenuates activated T cell‐induced OPC proliferation VEGFR2 inhibition attenuates VEGF‐A induced OPC proliferation.