William Lucas Lush (November 10, 1873 – August 28, 1951) was an American baseball player and college athletics coach and administrator. He played seven seasons of Major League Baseball from 1895 to 1904, including three with the Washington Senators. He later worked as a college athletics coach (mostly baseball and basketball) at Yale University, Columbia University, Fordham University, the United States Naval Academy, St. John's University, the University of Baltimore and Trinity College, Hartford. He also held athletic director positions at Fordham and the Naval Academy. In the 1930s, he coached athletic teams at Sing Sing prison in Ossining, New York.