Stephen Douglas Kevan (born 1954) is an American condensed matter physicist who researches "surface and thin film physics; electronic structure and collective excitations at surfaces; nanoscale spatial and temporal fluctuations in magnetic and other complex materials".[1] He is the current director of the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory in Berkeley, California.[2] He is also a faculty member on leave from the University of Oregon and served as division deputy for science at the ALS prior to his directorship.