Her Majesty's Most Honourable Privy Council is a body of advisors to the British Sovereign. Its members are largely senior politicians, who were or are members of either the House of Commons or House of Lords of the United Kingdom of Great Britain and Northern Ireland.

The Privy Council, the successor of the Privy Council of England, was formerly a powerful institution, but its policy decisions are now controlled by one of its committees, the Cabinet of the United Kingdom. It advises the Sovereign on the exercise of the Royal Prerogative, and issues executive orders known as Orders-in-Council and Orders of Council. Orders-in-Council make government regulations and appointments. Orders of Council are issued under the specific authority of Acts of Parliament, which delegate such matters to the Council, and are normally used to regulate public institutions. The Council advises on the issuing of Royal Charters, which grant special status to incorporated bodies and city and borough status to towns.

The Council also performs judicial functions, which are for the most part delegated to the Judicial Committee. The Committee consists of senior judges appointed as Privy Counsellors: justices of the Supreme Court of the United Kingdom, judges of the Court of Appeal of England and Wales, judges of the Court of Appeal in Northern Ireland and judges of the Inner House of the Court of Session (the supreme civil court of Scotland). It was formerly a supreme court of appeal for the entire British Empire, and continues to hear appeals from British Overseas Territories, Sovereign Base Areas, Crown Dependencies and some Commonwealth countries.