Many intertidal invertebrates in temperate regions, including the bay mussel (Mytilus trossulus) experience freezing temperatures during low tide in the winter. While M. trossulus can tolerate freezing of body fluids throughout the year, individuals collected in the winter and higher in the intertidal zone can survive lower temperature exposures. While the mechanisms of freeze tolerance in intertidal species are poorly understood, many other freeze tolerant organisms use ice-binding proteins (IBPs) to modulate internal ice formation. IBP functions can include preventing ice formation, controlling ice crystal growth and encouraging ice formation. We hypothesized that ice-binding proteins exist in intertidal species and play a role in the variation in freeze tolerance seen both seasonally and between intertidal regions. We used bioinformatic methods to investigate whether IBPs are found in mussel genomes, resulting in putative IBPs being found in various mussel species as well as multiple other intertidal organisms. Putative sequences were then further investigated to determine if they evolved through refunctionalization, non-sense DNA, or lateral gene transfer. We then collected M. trossulus monthly from both the high and the low intertidal zone. Using ice shell purification, we then successfully isolated putative IBPs from M. trossulus and characterized their activity. This is the first description of IBPs in intertidal animals and adds to our knowledge of the evolution of IBPs.