In 1986 he began working in Thoroughbred horse racing as a stable hand and eventually a training assistant. In 1994 he obtained his professional trainer's license and since the early 2000s has been a major figure on the California racing scene, with the largest stable in Southern California and one of the largest and most successful in the United States. He gained national attention for his Breeders' Cup wins and international recognition for winning the 2003 Japan Cup Dirt at Tokyo Racecourse.
Based at Hollywood Park Racetrack, O'Neill and his family reside in Santa Monica, California.
- ↑ Gruender, Scott A. (2007). Jockey: The Rider's Life in American Thoroughbred Racing. Jefferson, N.C.: McFarland. ISBN 9780786428199. http://books.google.com/books?id=dWAGY3i2skAC&pg=PT64&dq=%22Doug+O%27Neill%22+trainer&client=firefox-a&cd=2#v=onepage&q=%22Doug%20O%27Neill%22&f=false. Retrieved 2010-02-03.
- ↑ Free, Brad (2004-11-17). "ESPN.com - Horse Racing - Trainer Doug O'Neill staying put in California". Espn.go.com. http://espn.go.com/horse/news/2004/1116/1924098.html. Retrieved 2010-02-03.
- ↑ "Trainer Doug O'Neill surrounded by talent - Horse Racing - ESPN". Sports.espn.go.com. 2007-03-20. http://sports.espn.go.com/sports/horse/news/story?id=2806064. Retrieved 2010-02-03.
- ↑ "Bill Dwyre; Moving into the fast lane; O'Neill has earned plenty of money and attention as the trainer of Lava Man, but now he takes center stage with four possible Kentucky Derby runners". Los Angeles Times. 2007-04-06. http://pqasb.pqarchiver.com/latimes/access/1250621231.html?dids=1250621231:1250621231&FMT=ABS&FMTS=ABS:FT&type=current&date=Apr+06%2C+2007&author=Bill+Dwyre&pub=Los+Angeles+Times&desc=Bill+Dwyre%3B+Moving+into+the+fast+lane%3B+O%27Neill+has+earned+plenty+of+money+and+attention+as+the+trainer+of+Lava+Man%2C+but+now+he+takes+center+stage+with+four+possible+Kentucky+Derby+runners&pqatl=google. Retrieved 2010-02-03.
- ↑ "Trainer Doug O'Neill staying put in California". ESPN.com. November 17, 2004. http://espn.go.com/horse/news/2004/1116/1924098.html. Retrieved February 2, 2010.
- ↑ Gruender, Scott A. (2006). Jockey: The Rider's Life in American Thoroughbred Racing. McFarland. p. 52. ISBN 9780786428199.
- ↑ "Classic Success". The Blood-Horse. http://www.bloodhorse.com/horse-racing/articles/43459/classic-success. Retrieved February 2, 2010.
- ↑ "Derby is everything trainer once dreamed". Star Phoenix (Saskatoon). May 4, 2007. http://www.canada.com/saskatoonstarphoenix/news/sports/story.html?id=ca00b6ee-879d-45ef-8758-32d47c28ba89. Retrieved February 2, 2010.