Queen of Trumps (1832–1843) was a British
Thoroughbred racehorse and broodmare best known for winning the
classic Oaks and
St Leger Stakes in 1835, becoming the first horse to win both races. In a racing career which lasted from October 1834 until October 1836 she won ten of her eleven races. After being successful in her only race as a two-year-old, she defeated the
1000 Guineas winner
Preserve in the Oaks on her three-year-old debut. Later that year she started favourite for the St Leger and won from a field which included Preserve and the
Epsom Derby winner
Mundig. Queen of Trumps sustained her only defeat a few days later when she was attacked by a dog in the closing stages of the Scarborough Stakes. She was retired to stud after winning all four of her races in 1836. Queen of Trumps died in 1843 at the age of eleven. She was described by a contemporary writer as "certainly the most extraordinary mare these our days have seen".