Laurence Hugh Frost (July 22, 1902 – May 23, 1977) was a U.S. admiral who served as Director of Naval Intelligence and Director of the National Security Agency. Frost graduated from the U.S. Naval Academy in 1926 and served in various ships and shore stations throughout the 1920s and 1930s. He was the commanding officer of Greer (DD-145) when that destroyer was attacked by a German U-boat on 4 September 1941. This was the first attack by Germany on a U.S. warship during World War II and occurred while the U.S. was officially neutral, some three months before America entered the war.