Cancer stem cells (CSCs) play crucial roles in cancer progression, immune evasion, drug resistance, and recurrence. Understanding the mechanisms behind CSCs generation and stemness maintenance is vital for early cancer diagnosis and treatment. Here, we unveil that carnitine palmitoyltransferase 1A (CPT1A) is highly expressed in ovarian cancer stem cells (OCSCs) and is essential for maintaining stemness by regulating lipid desaturation. Studies confirmed that CPT1A enhances SREBP1 activation, upregulating SCD1 expression, and promoting lipid desaturation in OCSCs. Mechanistic studies reveal that CPT1A promotes succinylation of mitochondrial fission factor (MFF) through its lysine succinyltransferase (LSTase) activity, crucial for mitochondria-associated membranes formation and SREBP1 activation. Inhibiting CPT1A’s LSTase activity with Glyburide reduces OCSCs’ stemness and enhances cisplatin’s anti-tumor effects against ovarian cancer in vitro and in vivo. Together, our studies highlight the significance of CPT1A’s LSTase activity in maintaining OCSCs’ stemness, offering potential targets and therapeutic strategies for ovarian cancer treatment.© 2025. The Author(s).