Monomoy Girl is a retired American Thoroughbred racehorse who was the American Champion Three-Year-Old Filly of 2018 and Champion Older Female Horse of 2020. She showed very promising form as a juvenile in 2017 when she won her first three races before being narrowly beaten in the Golden Rod Stakes. In the following spring, she took the Rachel Alexandra Stakes and the Ashland Stakes before winning the Kentucky Oaks, the filly equivalent of the Kentucky Derby. She followed this up with wins in the Acorn Stakes and Coaching Club American Oaks, but was disqualified to second for interference in the Cotillion Stakes. She then rebounded to win the Breeders' Cup Distaff while facing older horses for the first time.

The Kentucky Derby is an American Grade I stakes race run at Churchill Downs in Louisville, Kentucky. The race is run by three-year-old Thoroughbreds at a distance of 1+1⁄4 miles. Colts and geldings carry 126 pounds and fillies 121 pounds.