Mark Thomas DeRosa (born February 26, 1975) is a Major League Baseball infielder for the St. Louis Cardinals. DeRosa is a utility player who has been primarily a second baseman, but can play other positions; he played six positions for the Chicago Cubs. He bats right-handed.

DeRosa was selected by the Atlanta Braves in the 7th round of the June 1996 free agent draft. In his 2,928 career at bats through 2009, he had a .278 batting average, 82 home runs, 815 hits, 453 runs, and 402 RBIs.

DeRosa was born in Passaic, New Jersey. He attended Bergen Catholic High School in Oradell, New Jersey where he earned all-state honors in baseball and in football.