Richard Salisbury Ellis CBE FRS (born 25 May 1950, Colwyn Bay, Wales) is Professor of Astrophysics at the University College London. He previously served as the Steele Professor of Astronomy at the California Institute of Technology (Caltech). He was awarded the 2011 Gold Medal of the Royal Astronomical Society,[2][3] in 2022 the Royal Medal[4] of the Royal Society and in 2023 the Gruber Prize in Cosmology.[5]