Peter Benjamin Mandelson, Baron Mandelson is a British former Labour Party politician, lobbyist and diplomat. He was the Member of Parliament (MP) for Hartlepool from 1992 to 2004. He served in Tony Blair and Gordon Brown's cabinets as Minister without portfolio, Secretary of State for Northern Ireland, Business Secretary and First Secretary of State. He was the British Ambassador to the United States in 2025 under Prime Minister Keir Starmer.
Mandelson served as director of communications from 1985 to 1990 during the leadership of Neil Kinnock. Sidelined during John Smith's leadership from 1992 to 1994, Mandelson became close to Blair and Brown.