The American Champion Three-Year-Old Filly is an American Thoroughbred horse racing honor awarded annually to a female horse in Thoroughbred flat racing.
The award originated in 1936 when both the Daily Racing Form (DRF) and Turf and Sports Digest (TSD) magazine began naming an annual champion.
Starting in 1950, the Thoroughbred Racing Associations (TRA) began naming its own champion.
In 1949, two Calumet Farm fillies, Wistful and Two Lea, shared the Champion's title after finishing equal top of the Daily Racing Form poll.
Champions from 1887 through 1935 were selected retrospectively by a panel of experts as published by The Blood-Horse magazine.