Reginald Van Trump Truitt (August 12, 1890 – April 11, 1991) was an American zoologist, Army officer, and college lacrosse player and coach. He spent his professional career studying the oyster habitat in the Chesapeake Bay. Truitt founded the Chesapeake Biological Laboratory at what is now the University of Maryland Center for Environmental Science. He also served as the first head lacrosse coach at his alma mater, the University of Maryland from 1919 to 1927. Truitt was inducted into the National Lacrosse Hall of Fame in 1959.