Robert Phillip Sharp (24 June 1911 – 25 May 2004) was an American geomorphologist and expert on the geological surfaces of the Earth and the planet Mars. Sharp served as the chairman of the Division of Geological Sciences at California Institute of Technology (Caltech) from 1952 to 1968. He built the modern department and especially recruited new faculty in geochemistry, tectonic geomorphology, planetary science, and field geology.