Objective <p>This review explores the important role of melatonin in ovarian function.</p> Background <p>The main manifestations of ovarian dysfunction are a decline in oocyte quality and a reduction in the number of follicles and oocytes. Current evidence suggests that environmental pollution, fungi, mycotoxins, drugs, and lifestyle are risk factors affecting ovarian function. Melatonin (MT) is an endogenous hormone synthesized by pineal gland cells, which has strong endogenous effects on scavenging free radicals and antioxidant damage. Previous studies have shown that melatonin plays a beneficial role in oocyte maturation, fertilization, and embryonic development. It can protect these cells from oxidative damage by clearing excessive free radicals, thereby regulating ovarian function and delaying ovarian aging.</p> Conclusions <p>This article reviews and discusses the relationship between melatonin and ovarian function regulation, including the synthesis and secretion of melatonin, the local synthesis and main role of melatonin in the ovaries, and the alleviating effect of melatonin on ovarian function decline caused by different injury factors.</p> Significance <p>This review provides important theoretical basis for clinical regulation of ovarian function.</p>