Unbridled (March 5, 1987 – October 18, 2001) was a Champion American Thoroughbred racehorse.

The colt was sired by Fappiano (10 wins in 17 starts), by Mr. Prospector, and his dam Gana Facil, by Le Fabuleux. Unbridled retired with a career record of 8 wins, 6 places and 6 shows in 24 starts, and $4,489,475 in career earnings. Unbridled had a great rivalry with Summer Squall over their three and four year old seasons. Summer Squall defeated Unbridled in 4 of their 6 meetings.

In 1989 at age two, Unbridled won the “What A Pleasure Stakes” and placed in all six of his starts. At age three, ridden by jockey Craig Perret, he won the Grade I Florida Derby by four lengths and America’s most prestigious race, the Kentucky Derby by 3½ lengths. He finished second in the Preakness Stakes to Summer Squall then in a major upset, finished fourth in the Belmont Stakes to the Irish colt, Go And Go. In the fall, ridden by Pat Day, Unbridled won the 1¼ mile Breeders’ Cup Classic at Belmont Park in 2:02.20 minutes. His performance for the year earned him the prestigious Eclipse Award as Champion 3-year-old male of 1990.
Unbridled’s Kentucky Derby win provided one of the most memorable moments in that race’s history. A network television camera in the Churchill Downs stands captured Unbridled’s trainer, Carl Nafzger, giving the horse’s elderly owner, Frances Genter, an exciting stretch call because of her poor vision. Nafzger shouted, “He’s going to win! He’s going to win! Oh, Mrs. Genter, I love you!”

Racing as a four year old, Unbridled won the Deputy Minister Handicap at Gulfstream Park and placed second behind Summer Squall in the Fayette Handicap at Keeneland Race Course.

Unbridled sired 292 runners that produced 183 winners (38 of those stakes winners) out of 437 foals earning over $31 million by 2000. Ten of his offspring were Grade I Stakes winners, four were classic winners, and three received Eclipse Awards. Unbridled is the last Kentucky Derby winner to sire another Derby winner, Grindstone, who placed first in the Kentucky Derby in 1996.

Unbridled is also the last stallion to have sired at least one winner in each of the American Triple Crown races (first for each listed): Grindstone, Kentucky Derby, 1996; Red Bullet, Preakness Stakes, 2000; and Empire Maker, Belmont Stakes, 2003.

Some of Unbridled’s other offspring includes:

Colts/Horses: Unbridled’s Song, Eddington, Anees, Unshaded, Saarland, Mustanfar, Symphony Sid, Rebridled, Malabar Gold, Unbridled Jet, Unbridled’s Image, Niigon, Greed is Good, Wheelaway, Unrestricted, Broken Vow, Pupil, and Uncoupled.

Fillies/Mares: Banshee Breeze, Halfbridled, Exogenous, Santa Catarina, Surya, Lady Ballade, Happily Unbridled, Boom Town Girl, Unrestrained, Manistique and Belterra.

Unbridled was also grandsire of the filly Eight Belles (sired by Unbridled’s Song). Eight Belles finished second at the 2008 Kentucky Derby, but she broke both front pasterns at the finish and was euthanized on the track. Via his daughter Oatsee, he was also the broodmare sire of Shackleford, winner of the 2011 Preakness Stakes.

One of Grindstone’s foals, Birdstone, would upset Smarty Jones to win the 2004 Belmont Stakes. Birdstone would in turn sire Mine That Bird, a gelding that won the 2009 Kentucky Derby, and Summer Bird, a colt that won the 2009 Belmont Stakes, giving Unbridled three generations of Triple Crown race winners.

In September 2001, Unbridled underwent two operations at Hagyard Equine Medical Institute, near Lexington, Kentucky.