- Bats Left, Throws Right
- Height 5' 9", Weight 190 lb.
- School University of Texas at Austin
- High School Socorro High School
- Debut July 31, 2005
Shortstop Omar Quintanilla was drafted by the Oakland Athletics in the 1st round of the 2003 amateur draft. He was signed by scout Tim Holt and began his professional career in 2003, splitting the season between the Vancouver Canadians and the Modesto A's. He began the next year at Modesto, where he hit .315 with 72 RBI before being promoted late in the season to the Midland Rockhounds with whom he hit .351.
In 2005, Quintanilla played for Midland again to start the season and hit .293 in 78 games with the club. On July 13 of that year, he was sent, along with Eric Byrnes to the Colorado Rockies for pitchers Joe Kennedy and Jay Witasick. He then played 13 games for the AAA Colorado Springs Sky Sox before being promoted to the majors in late July. He spent most of August as the Rockies starting shortstop while Clint Barmes was out due to injury. He began 2006 back at Colorado Springs but was returned to the Rockies in June.
In 2010, Quintanilla was suspended for 50 games for violating MLB's banned substance policy.