Guillermo Antonio Quiroz
- Bats Right, Throws Right
- Height 6' 1", Weight 202 lb.
- Debut September 4, 2004
- Final Game September 13, 2014
- Born November 29, 1981 in Maracaibo, Zulia, Venezuela
Venezuelan catcher Guillermo Quiroz was signed by scout Emilio Carrasquel and the Toronto Blue Jays for $1.2 million in September 1998. He made his pro debut with the Medicine Hat Blue Jays of the Pioneer League the following year and led the team with 9 home runs. Quiroz spent the next two seasons at Class A before reaching the Eastern League in 2002. That year, with the New Haven Ravens, he had his finest season at the plate, hitting .282 with 20 homers and 79 RBIs. He remained with the Ravens in 2003 and again hit 20 home runs.
In 2004, he joined the AAA Syracuse Sky Chiefs and in September he made his big league debut. He started 15 games for the Blue Jays and hit .213 for the club. In 2005, Quiroz began the season on the disabled list with a shoulder injury and later suffered a collapsed lung. He went on to play for the Class A Dunedin Blue Jays before returning to Syracuse in late July. Just over a month later, he returned to the majors and made a dozen starts for the Jays.