Endometriosis (EM) refers to the implantation or growth of endometrial glands and stroma outside the uterus. The pathological mechanism of EM includes immunoinflammatory changes, oxidative stress, epithelial-stromal transition and neovascularization. EM tends to occur in women of reproductive age and seriously affects the reproductive health and quality of life of patients. At present, it is mainly treated through surgery and long-term drug management. Melatonin is an endogenous indoleamine hormone, which has various physiological functions such as antioxidant, anti-inflammatory, immune regulation and apoptosis promotion through different signaling pathways. It has attracted much attention in the treatment of cancer, cardiovascular diseases and nervous system diseases. Recent studies have found that melatonin can also inhibit the development of EM by inhibiting estrogen synthesis and antagonizing angiogenesis, and can effectively relieve pelvic pain. This article reviews the research progress on melatonin in EM in order to provide new ideas for drug therapy of EM.