Michael James Holtz (born October 10, 1972 in Arlington, Virginia) is a former middle relief pitcher in Major League Baseball who played from 1996 through 2006 for the California Angels (1996), Anaheim Angels (1997-2001), Oakland Athletics (2002), San Diego Padres (2002), and Boston Red Sox (2006). He bats and throws left-handed.
In an eight-season career, Holtz posted a 16-19 record with a 4.76 ERA and three saves in 353 relief appearances.
Following the bulk of his major league career, Holtz played for the Yokohama BayStars of the Japanese Central League in 2005 and had a 0-1 mark with 4.38 ERA and 22 strikeouts in 24 ⅔ innings of work. He came back to the majors to pitch in three games for the Red Sox in 2006.
He opened his own baseball training facility, ERA (Earned Respect Athletics) Sports Inc. Located in Johnstown, and Altoona, PA.