Paul Kuykendall Dayton (born April 8, 1941 in Tucson, Arizona) is a biological oceanographer and marine ecologist at the Scripps Institution of Oceanography. Dayton works in benthic ecology, marine conservation, evolution, natural history, and general ecology. During a 35-year career at Scripps, Dayton has researched coastal Antarctic habitats and the rocky shore habitats of Washington in order to better understand marine ecosystems. He has also documented the environmental impacts of overfishing, and phenomena such as El Niño on coastal ecology.