The office of Downing Street Chief of Staff is the most senior political appointee in the Office of the Prime Minister of the United Kingdom, acting as a senior aide to the Prime Minister of the United Kingdom. The holder of the office retains a highly powerful, non-ministerial position within His Majesty's Government. The incumbent chief of staff is Liam Booth-Smith, who was installed in the position by Rishi Sunak upon his accession as prime minister in October 2022.