Warrick Couch has undertaken world-leading research in the areas of galaxy evolution and cosmology. He has made fundamental contributions to understanding the impact the environment has on galaxy evolution. This includes pioneering work on tracking changes in star formation activity and morphology in cluster galaxies with cosmic time, which established that these galaxy properties have been fundamentally transformed within these dense environments over the last 5–8 billion years. He was also a founding member of the Supernova Cosmology Project that was one of the two teams awarded the 2007 Gruber Cosmology Prize for discovery of an accelerating universe.