Sergio Valdez (born September 7, 1964) is a former professional baseball pitcher in Major League Baseball who played from 1986 through 1995 with the Montreal Expos (1986, 1992–93), the Atlanta Braves (1989–90), the Cleveland Indians (1991–92), the Boston Red Sox (1994), and San Francisco Giants (1995).

On September 10, 1986, Valdez made his major league debut against the New York Mets giving up five earned runs and nine hits through six innings to record his first major league loss.

He returned to the majors after leaving in 1989 as a reliever, starting just one in 19 appearances, and earning a 6.06 ERA with a 1-2 record.

He was selected off waivers from the Braves by the Indians on April 30, 1990.

This biographical article relating to a Dominican Republic baseball pitcher is a stub.