Denis Winston Healey, Baron Healey, was a British Labour Party politician who served as Chancellor of the Exchequer from 1974 to 1979 and as Secretary of State for Defence from 1964 to 1970; he remains the longest-serving Defence Secretary to date. He was a Member of Parliament from 1952 to 1992, and was Deputy Leader of the Labour Party from 1980 to 1983. To the public at large, Healey became well known for his bushy eyebrows, his avuncular manner and his creative turns of phrase.

The Secretary of State for Defence, also known as the Defence Secretary, is a secretary of state in the Government of the United Kingdom, with responsibility for the Ministry of Defence. As a senior minister, the incumbent is a member of the Cabinet of the United Kingdom.