Sleep disorders have become a global health issue, with a prevalence rate of 16.4% to 25.0%. Although drug treatments are effective in the short term, they have limitations in terms of dependence, tolerance and residual daytime effects. Dietary intervention, with its advantages of natural origin, high safety, and multi-target synergy, has become a research hotspot in sleep medicine. This article primarily focuses on four major food functional factors including amino acids, polyphenols, saponins, and polysaccharides, as well as other food-derived components with the potential to improve sleep, such as fatty acids, micronutrients, and probiotics. This paper reviews their sleep regulation mechanisms, and summarizes relevant clinical trials, providing theoretical support for the development of functional foods for sleep health and promoting the transformation and application of the “food-based alternatives to medicine” strategy in sleep regulation. Currently, some sleep regulatory factors have been applied to functional foods, but they still need to be clarified in terms of optimal intake, threshold of efficacy, and interaction mechanism with other active ingredients. With the advancement of technology and in-depth research, the sleep-improving potential of food functional factors will have greater research value and broader application prospects.