Sergio Alberto Contreras (born April 30, 1980) is a Mexican former professional baseball outfielder and first baseman.

His first professional year started out a little bumpy-in 63 games with the Angels of the Dominican Summer League, he hit only .252 with 2 home runs and 33 RBI.

His 2006 season also was in the Mexican League, this time with the Tigres de la Angelopolis.

Contreras has never had a great eye at the plate, not once in his professional career has he walked more than 50 times in a season.

Contreras played for the Tigres de Quintana Roo in the Mexican League from 2005 to 2017.