Chemoselective ligation reactions are highly efficient and specific covalent bond forming reactions capable of proceeding within a physiological environment. Chemoselective ligations offer exquisite specificity, similar to enzymatic reactions, but with the significant advantage of accessing a much broader range of coupling partners. Thus, even among a multitude of reactive functional groups, two ligation partners exclusively react with one another. While chemoselective ligation has been used in many applications, the focus of this review is the application of chemoselective ligation reactions toward carbohydrate-based structures. More specifically, recent applications are presented in areas such as immobilized carbohydrate arrays, cell-surface engineering, glycoproteins / peptides, and glycosylated natural products.