Robert Edmund Sangster (May 23, 1936 - April 7, 2004) was a well-known English racehorse owner and breeder.

He was the son of Vernon Sangster , founder of the Vernons Pools business. Sangster was chairman of the Vernons Organisation from 1980 to 1988, selling it in 1988 for £90 million.

He spent millions on his thoroughbred racing and breeding empire that included interests in Australia, England, Venezuela, the United States, Ireland, France, and New Zealand. His racing colours were emerald green and royal blue. His successes included winning two Epsom Derbys, four Irish Derbys, two French Derbys, and three Prix de l'Arc de Triomphes. His jockeys included Lester Piggott, Pat Eddery and Steve Cauthen.

Sangster was married three times: first to Christine Street, by whom he had three sons (Guy, Ben and Adam) and a daughter. The marriage ended in 1978, when he left her for socialite Susan Peacock, wife of an Australian politician. His second marriage did not last long, with Sangster having well-publicized affairs with Jerry Hall and Susan Lilley. Sangster married Susan Lilley in 1985, and the couple had two sons. The marriage ended in divorce in 2000.

Sangster died of pancreatic cancer on April 7, 2004. age 67.