This paper describes a rare case of unilateral Sertoli–Leydig cell ovarian tumor with AFP elevation that caused amenorrhea in an adolescent patient and presents a comprehensive literature review of ovarian Sertoli–Leydig cell tumors, focusing on their clinical presentation, laboratory findings, macroscopic and histopathological features, genetics, clinical management, prognostic factors and follow-up, which adds practical relevance and might aid clinicians in decision-making. The gene discussed is AFP; the disease is Ovarian Leydig Cell Tumor.