The 2021 Cambridgeshire and Peterborough mayoral election was held on 6 May 2021 to elect the mayor of Cambridgeshire and Peterborough. The supplementary vote system was used to elect the mayor for a four-year term of office. Subsequent elections will be held in May 2025 and every four years thereafter. The election was held alongside a full election for Cambridge City Council, the Cambridgeshire Police and Crime Commissioner, Cambridgeshire County Council and one-third of Peterborough City Council and a number of District and parish by-elections.