Martin John Krug (10 September 1888 – 27 June 1966) was a Koblenz, Germany-born major league infielder with the Boston Red Sox (1912) and Chicago Cubs (1922).
He was a backup shortstop for the 1912 World Series champion Red Sox, but had little opportunity to play behind starter Heinie Wagner.
He was primarily a third baseman for the 1922 Cubs.