Moncrieff Johnston Spear (born September 24, 1921) is an American former diplomat. Spear was born in New York and attended Cornell University (B.A. 1946) and George Washington University (M.A. 1952). He is a World War II veteran, serving with the United States Navy. After the war, in 1946, Spear joined the United States Foreign Service. He was the United States Chargé d'Affaires ad interim in the Bahamas at the opening of the U.S. Embassy in 1973. He married Lois Stamey and has two children.