The Secretary of State for Defence is the senior United Kingdom government minister in charge of the Ministry of Defence.
The post was created on 1 April 1964 and combined the former cabinet positions of First Lord of the Admiralty, Secretary of State for War and Secretary of State for Air. The separate offices of the Admiralty, War Office and the Air Ministry were abolished and their functions transferred to an expanded Ministry of Defence.
- Peter Thorneycroft (1964-1964)
- Denis Healey (1964-1970)
- Peter Carington, Lord Carrington (1970-1974)
- Ian Gilmour (1974)
- Roy Mason (1974-1976)
- Frederick Mulley (1976-1979)
- Francis Pym (1979-1981)
- John Nott (1981-1983)
- Michael Heseltine (1983-1986)
- George Younger (1986-1989)
- Tom King (1989-1992)
- Malcolm Rifkind (1992-1995)
- Michael Portillo (1995-1997)
- George Robertson, Lord Robertson (1997-1999)
- Geoff Hoon (11 October 1999-)