Abstract The one-carbon metabolism enzyme methylenetetrahydrofolate dehydrogenase/cyclohydrolase 2 (MTHFD2) is a promising therapeutic target in cancer. MTHFD2 is upregulated across numerous cancer types, promotes growth and metastasis of cancer, and correlates with poorer survival. Recent studies have developed small molecule inhibitors of the isozymes MTHFD2 and MTHFD1 that show promise as anti-cancer agents through different mechanisms. This review discusses the current understanding of the function of MTHFD2 in cancer and the status of inhibitors for treating MTHFD2-overexpressing cancers.