Mark Thomas DeRosa (born February 26, 1975) is a Major League Baseball player for the San Francisco Giants. DeRosa is a utility player who has been primarily a second baseman, but can play other positions, including the outfield; 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 3,165 career at bats through 2009, he had a .275 batting average, 92 home runs, 869 hits, 484 runs, and 430 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.