Oxygen (foaled 1828, died in winter 1854–1855) was a British Thoroughbred racehorse and broodmare who won the classic Oaks Stakes at Epsom Downs Racecourse in 1831. In a racing career which lasted from July 1830 until April 1833 she won eight of her fifteen races and finished second on five occasions. Oxygen's Oaks was the last of twenty classic wins for her owner George FitzRoy, 4th Duke of Grafton.