Moses Edwin Clapp (May 21, 1851 – March 6, 1929) was an American lawyer and politician. Born in Delphi, Indiana, Clapp moved with his parents to Hudson, Wisconsin. He went to University of Wisconsin Law School and practiced law in Hudson, Wisconsin. He was district attorney for St. Croix County, Wisconsin. He then moved to Fergus Falls, Minnesota where he practiced law.He served as the Minnesota Attorney General from 1887 until 1893.