•Antifreeze proteins (AFPs) are a sub-set of ice-binding proteins (IBPs).•IBP functions include ice recrystallization inhibition and adhesion to ice.•IBPs have diverse structures but ice-binding sites with similar properties.•IBPs may organize ice-like waters on their surface to promote binding to ice.•Ice nucleating proteins might function in a similar way but on a larger scale. Antifreeze proteins (AFPs) were discovered in marine fishes that need protection from freezing. These ice-binding proteins (IBPs) are widespread across biological kingdoms, and their functions include freeze tolerance and ice adhesion. Consistent with recent independent evolution, AFPs have remarkably diverse folds that rely heavily on hydrogen- and disulfide-bonding. AFP ice-binding sites are typically flat, extensive, relatively hydrophobic, and are thought to organize water into an ice-like arrangement that merges and freezes with the quasi-liquid layer next to the ice lattice. In this article, the roles, properties, and structure–function interactions of IBPs are reviewed, and their relationship to ice nucleation proteins, which promote freezing at high subzero temperatures, is explored.