Joseph Gilbert Hamilton (November 11, 1907 – February 18, 1957) was an American professor of Medical Physics, Experimental Medicine, General Medicine, and Experimental Radiology as well as director (1948-1957) of the Crocker Laboratory, part of the Lawrence Berkeley National Laboratory. Hamilton studied the medical effects of exposure to radioactive isotopes, which included the use of unsuspecting human subjects. He was married to painter Leah Hamilton.