The Permanent Under-Secretary of State for Defence,[1][2] also called the Permanent Secretary to the Ministry of Defence,[3][4] is the permanent secretary at the Ministry of Defence.

The office holder is the government's principal civilian adviser on Defence matters.

[6] They are the MOD Principal Accounting Officer,[5] and are called to give evidence to the Defence Select Committee.

The current Permanent Secretary to the MOD is David Williams.

[4] The Permanent Secretaries at the earlier Ministry of Defence (1947–1964):[9]