Extracellular polysaccharides produced by lactic acid bacteria represent a class of bioactive polymers that play an important role in both the technological and health-related features of fermented food. This chapter gives a comprehensive overview of EPS, considering their molecular diversity, biosynthesis pathways, and regulation in LAB. Attention will be paid to the functional contributions of EPS in improving texture, viscosity, and fermentation kinetics of dairy and nondairy products. It also deals with the health-related functionalities of EPS, such as antioxidant activity, anti-inflammatory activity, cholesterol-lowering activity, antimicrobial activity, gut health modulation activity, and more. Further, it discusses industrial applications of EPS mainly in improving the quality of fermented foods, and recent technological advances in optimizing the production of EPS.