In the food industry and functional food sector, Stevia rebaudiana Bertoni has gained notable attention as a natural sweetener with commercial value and health benefits. Its leaves contain steviol glycosides, which are high-intensity, zero-calorie sweetening compounds that serve as ideal alternatives to artificial sweeteners. Notably, growing evidence suggests that beyond its sweetening properties, stevia and its active components exhibit multiple pharmacological effects, including antioxidant and anti-inflammatory activities, management of metabolic disorders, anticancer and cell cycle regulation, gastrointestinal and hepatorenal protection, and antibacterial and oral health benefits. These properties make stevia a promising natural material for broad applications in food products, dietary supplements, animal feed, and environmental remediation. This study systematically reviews the chemical composition, pharmacokinetic characteristics, pharmacological properties, and safety profile of the bioactive compounds in stevia while highlighting its innovative applications in food, healthcare, and agriculture. Recent advances in the biosynthesis of steviol glycosides, with particular focus on strategies to facilitate the industrial-scale production of rebaudioside M, are also discussed. The collected data provide scientific foundations for the expanded utilization of stevia across multiple settings, with a goal of promoting the sustainable development of high-value, diversified stevia-based products.