Sir Denis Thatcher, 1st Baronet, (10 May 1915 – 26 June 2003) was a British businessman and the husband of Margaret Thatcher, who served as Prime Minister of the United Kingdom from 1979 to 1990.
He was the first male spouse of a British prime minister.
As of 2019, Thatcher is the last commoner awarded a hereditary title; he was granted the Thatcher baronetcy in 1990.