What A Summer (foal in 1973) was an American Thoroughbred Champion racehorse who defeated both male and female competitors.
What A Summer was trained very early in her career by Hall of Fame conditioner Bud Delp while racing for her breeder, Milton Polinger.
What A Summer did not start racing until near the end of her two-year-old season, when she broke her maiden at Philadelphia Park.
Her jockey, Chris McCarron, was credited with a solid ride by conserving energy with moderate fractions in the middle portion of the race.
In December 1976, What A Summer won the $50,000 Anne Arundel Stakes at Laurel Park Racecourse, beating Turn the Guns and Avum in 1:38.20 for the mile under McCarron.
In 1977, What A Summer won the $75,000 Fall Highweight Handicap twice, carrying the high weight of 134 pounds under jockey Jacinto Vásquez.
Her most memorable race was perhaps her dominating performance in the de facto second leg of the filly Triple Crown, the Black-Eyed Susan Stakes.