Hydrocolloids comprise a number of polysaccharides with applications both in the food industry and beyond. One such application is as a wall material in microencapsulation processes. This chapter covers the most common encapsulating hydrocolloids, with a special focus on the two that are most frequently studied, gum arabic and sodium alginate. It also discusses a number of the applications within the food industry where microencapsulation with these ingredients is useful. Attention is paid to recently published research regarding the use of hydrocolloids in coating antioxidants, flavors, microorganisms, lipids, enzymes, and anti-bacterial materials. Information is included about appropriate choice of wall materials and methods for each of these purposes, including which hydrocolloids might be ideal for spray drying, coacervation, and ionic gelation processes