The Permanent Secretary, in most departments officially titled the Permanent Under-Secretary of State (although the full title is rarely used), is the senior civil servant of a British Government ministry, charged with running the department on a day-to-day basis. The Permanent Secretary is usually created a Knight or Dame Commander of the Order of the Bath if not already holding the title. Some larger departments also have a Second Permanent Secretary who acts as deputy.

The most famous (albeit fictional) Permanent Secretary is probably Sir Humphrey Appleby of the BBC TV series Yes, Minister.