John Leonard "Doc" Lavan (October 28, 1890 – May 29, 1952) was an American professional baseball shortstop who played in Major League Baseball (MLB) for the St. Louis Browns, Philadelphia Athletics, Washington Senators, and St. Louis Cardinals. Born in Grand Rapids, Michigan, Lavan attended both Hope College and the University of Michigan from 1908 to 1911 before playing in the major leagues.