Evelyn Mansfield King (30 May 1907 – 14 April 1994) was a British member of parliament for both the Labour Party and then the Conservative Party.
The son of Harry Percy King and Winifred Elizabeth née Paulet, King was educated at Cheltenham College and King's College, Cambridge University (where he was the university's correspondent to the Sunday Times, 1928–30). He then entered the Inner Temple, London. He was Assistant Master at Bedford School, taught at Craigend Park School, and became Headmaster and Warden of Clayesmore School, 1935-1950. He revitalised a financially failing Clayesmore, bringing with him some pupils from Craigend Park, and managing the school in an energetic and proactive way, putting it on the Headmasters' Conference List, and generally on the map. During World War II he served in the Gloucestershire Regiment from 1940 and was promoted Acting Lieutenant-Colonel in 1941.
King was originally Labour Party Member of Parliament for Penryn and Falmouth from 1945 to 1950, and served as Parliamentary Secretary at the Ministry of Town and Country Planning 1947 to 1950. He contested Poole in 1950 but lost.
King defected to the Conservative Party in 1951 and contested Southampton Itchen in 1959. In 1964, he stood in South Dorset and unseated Labour's Guy Barnett, who had gained the seat in a by-election two years earlier.