Ovarian cancer (OC) is the seventh most common cancer among women globally and the tenth in China. Epithelial OC is the most prevalent subtype, with five major histotypes: high-grade serous (HGSOC), endometrioid (ENOC), clear cell (CCOC), mucinous (MOC), and low-grade serous (LGSOC). Genetic susceptibility is mediated by rare inherited mutations with high to moderate penetrance, and genome-wide association studies have identified 29 common susceptibility alleles, including 14 subtype-specific alleles. Reproductive and hormonal factors, such as parity, oral contraceptive use, and lactation, can lower risk, while older age at menopause and hormone replacement therapy increase risk. These associations vary by histotype, particularly for mucinous OC. Other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, may also influence OC risk, though the evidence is less clear. Environmental and lifestyle factors, including asbestos exposure and cigarette smoking, are also potential risk factors. The epidemiology of OC provides insights into etiology, primary prevention, early detection, and therapeutic strategies.Ovarian cancer (OC) is the seventh most common cancer among women globally and the tenth in China. Epithelial OC is the most prevalent subtype, with five major histotypes: high-grade serous (HGSOC), endometrioid (ENOC), clear cell (CCOC), mucinous (MOC), and low-grade serous (LGSOC). Genetic susceptibility is mediated by rare inherited mutations with high to moderate penetrance, and genome-wide association studies have identified 29 common susceptibility alleles, including 14 subtype-specific alleles. Reproductive and hormonal factors, such as parity, oral contraceptive use, and lactation, can lower risk, while older age at menopause and hormone replacement therapy increase risk. These associations vary by histotype, particularly for mucinous OC. Other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, may also influence OC risk, though the evidence is less clear. Environmental and lifestyle factors, including asbestos exposure and cigarette smoking, are also potential risk factors. The epidemiology of OC provides insights into etiology, primary prevention, early detection, and therapeutic strategies.