The Parliament of the United Kingdom of Great Britain and Northern Ireland, commonly known as the British Parliament, is the supreme legislative body in the United Kingdom, British Crown dependencies and British overseas territories. It is located in Westminster, London. Parliament alone possesses legislative supremacy and thereby ultimate power over all other political bodies in the UK and its territories. At its head is the Sovereign, Queen Elizabeth II.

The parliament is bicameral, with an upper house, the House of Lords, and a lower house, the House of Commons. The Queen is the third component of the legislature. The House of Lords includes two different types of members: the Lords Spiritual (the senior bishops of the Church of England) and the Lords Temporal (members of the Peerage) whose members are not elected by the population at large, but are appointed by the Sovereign on the advice of the Prime Minister. Prior to the opening of the Supreme Court in October 2009 the House of Lords also performed a judicial role through the Law Lords.