Melatonin is a key hormone that regulates the sleep–wake cycle and supports the body’s biological rhythm. It plays a vital role in improving sleep quality, energy production, and mental concentration. This study explores the physiological functions of melatonin, its effects on sleep, and the natural ways to enhance melatonin levels through diet. The research also demonstrates how melatonin supplementation can temporarily aid sleep improvement, followed by a transition to maintaining healthy sleep naturally.