Fusaichi Pegasus (Japanese: フサイチペガサス, Japanese pronunciation: [ɸɯ̥saꜜitɕi pegasas]; April 12, 1997 – May 23, 2023) was a champion American Thoroughbred racehorse who won the 2000 Kentucky Derby, and subsequently set a record at auction—selling for US$70M to Coolmore Stud.

The colt was purchased as a yearling for $4 million by Fusao Sekiguchi, which is the highest price paid for a Kentucky Derby winner.^[2][3] His name is a combination of his owner's name, "Fusao", and the Japanese word for one, "ichi", to mean No. 1 or the best; the second half of his name came from that of a winged horse in Greek mythology.^[4][5]

Nicknamed "Fu Peg",^[2] he was a son of Mr. Prospector and Angel Fever, a mare by leading sire Danzig.^[1]

In early 2000, Fusaichi Pegasus won the Grade 2 San Felipe Stakes and Wood Memorial Stakes.^[2]

Fusaichi Pegasus won the 2000 Kentucky Derby in a time of 2:01.12 for the 11⁄4 mile distance.^[6] At the time, it was the seventh fastest time in Kentucky Derby history; by the time of his death, it was the tenth fastest time.^[3] He was the first favorite to win the Kentucky Derby since Spectacular Bid in 1979 and the first horse to win the Kentucky Derby without winning a race as a two-year-old since Proud Clarion in 1967.^[4] He then lost to Red Bullet in the Preakness Stakes. After his loss in the Preakness Stakes, he did not race in the third leg of the Triple Crown, the Belmont Stakes.^[3]

In 2000, he was sold to Irish breeder Coolmore Stud for a reported price of more than US$70 million (£35m).^[7] The previous record for a stallion prospect was US$40m (£24m), paid in 1983 for Shareef Dancer.^[7] During his first decade as a stallion, he split his time between Coolmore's Ashford Stud and Coolmore's Australian breeding operation.^[3] He shuttled in 2008 to Haras Don Alberto in Chile,^[8] and also shuttled in Uruguay.^[9] Among his progeny are Grade 1 winners Bandini, Roman Ruler, Champ Pegasus, and Haradasun.^[9]

His son Roman Ruler produced Ruler on Ice, winner of the 2011 Belmont Stakes.^[10] He was pensioned from stud duty after the 2020 breeding season.^[11]

Fusaichi Pegasus died on May 23, 2023, at age 26. He was euthanized due to the effects of old age.^[9][12]