The permanent under-secretary of state for defence, also called the permanent secretary to the Ministry of Defence, is the permanent secretary at the Ministry of Defence. The office holder is the government's principal civilian adviser on defence matters. The office holder is a member of the Defence Council and the Defence Board. They are the MOD principal accounting officer, and are called to give evidence to the Defence Select Committee.

The position has existed in its current format since the formation of the modern Ministry of Defence in 1964. It was preceded by the permanent secretary at the earlier Ministry of Defence (1947–1964), and by the permanent secretaries at the government departments that were absorbed into the Ministry of Defence in 1964: the permanent secretary to the Admiralty, the permanent under-secretary of state for war, and the permanent secretary to the Air Ministry.

The current permanent secretary for the Ministry of Defence is Jeremy Pocklington.

Responsibilities Leading defence (with CDS); Setting strategy for defence, including corporate strategy (subject to ministers’ direction, and together with CDS); Heading the Department of State and the MOD Civil Service; Providing policy advice to ministers and leading the relationship with other government departments; The overall organisation, management and staffing of defence; Performing the full range of Accounting Officer responsibilities, including the delegation of financial and other authority and accountability to senior colleagues, with personal accountability to Parliament for the economic, efficient and effective use of defence resources.

Permanent secretaries to the Ministry of Defence 1947–1964 The permanent secretaries at the earlier Ministry of Defence (1947–1964):David Butler and Gareth Butler, Twentieth Century British Political Facts 1900–2000, eighth edition, Macmillan, 2000, p. 302 1947: Sir Henry Wilson Smith 1948: Sir Harold Parker 1956: Sir Richard Powell 1960: Sir Edward Playfair 1961: Sir Robert Scott 1964: Sir Henry Hardman

1964–present Henry Hardman (1964–1966) James Dunnett (1966–1974) Michael Cary (1974–1976) Frank Cooper (1976–1982) Clive Whitmore (1982–1988) Michael Quinlan (1988–1992) Christopher France (1992–1995) Richard Mottram (1995–1998) Kevin Tebbit (1998–2005) Bill Jeffrey (2005–2010) Ursula Brennan (2010–2012) Jon Thompson (2012–2016) Stephen Lovegrove (2016–2021) David Williams (2021–2025) Jeremy Pocklington (2025-)

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