This study aimed to investigate the role of Acyl-CoA medium-chain synthetase 3 (ACSM3) in ovarian cancer (OC) progression. ACSM3 expression in OC tissues and cells is detected by real-time quantitative polymerase chain reaction, immunohistochemistry, or western blot. The influences of ACSM3 on OC progression are assessed in vitro and in vivo experiments. Gene set enrichment analysis is performed to find significantly enriched pathways related to ACSM3. In this study, ACSM3 expression in OC tissues and cells is downregulated. ACSM3 inhibited tumor growth in vivo. Knockdown of ACSM3 promoted cell proliferation, migration, and invasion, inhibited cell apoptosis, and activated JAK/STAT3 signaling pathway in SKOV3 cells, while overexpression of ACSM3 in A2780 cells led to the opposite results. Moreover, treatment with interferon-gamma (IFN-γ) in A2780 cells reversed the effects of ACSM3 on cell proliferation, migration, invasion, and apoptosis, but IFN-γ further enhanced the effects of ACSM3 knockdown on SKOV3 cell proliferation, migration, invasion, and apoptosis. In conclusion, ACSM3 inhibited OC cell proliferation, migration, and invasion, and promoted cell apoptosis by suppressing the IFN-γ/JAK/STAT3 signaling pathway, which might provide a promising therapeutic target for OC treatment.