British politician, member of the Labour Party, and, from the 1970s, unofficial leader of the party's radical populist left.

Though a fierce critic of the British class system, Benn came from a moneyed and privileged family himself. Both of his grandfathers had been members of Parliament, and his father, William Wedgwood Benn (1877–1960), had been a Liberal and then a Labour MP who in 1942 entered the House of Lords as 1st Viscount Stansgate. The younger Benn joined the Labour Party in 1943, attended New College, Oxford (M.A., 1949), and was first elected to Parliament in 1950. Anticipating that inheritance of his father's title would immediately disqualify him from continuing to serve in the House of Commons, he introduced a personal bill to permit him to renounce the title. The bill was defeated, but, after his father's death in 1960, he continued the struggle, and in 1963 the Peerage Act enabled peers to renounce their titles for their lifetimes. Benn not only renounced his viscountcy (July 31, 1963) but later shed the names with which he had been christened, Anthony Neil Wedgwood, to become simply Tony Benn.

When Labour formed a government under Harold Wilson in 1964, Benn became postmaster general in 1964 and was minister of technology from 1966 to 1970. When Labour was in power again from 1974 to 1979 under first Wilson and then James Callaghan, Benn was secretary of state for industry and minister for posts and telecommunications (1974–75) and secretary of state for energy (1975–79). In 1981, after he led a successful fight for Labour's left wing to wrest control of leadership selection from members of Parliament (MPs), which prompted prominent Labour MPs associated with the party's right wing to form a new political party, the Social Democratic Party, Benn challenged Denis Healey for deputy leader of the party. His campaign prompted intense internecine conflict in the party and ended with his narrow defeat (less than 1 percent) by Healey. Benn lost his parliamentary seat in the elections of 1983 but returned to Commons in a by-election in 1984.

During the 1970s and '80s he became the most influential of left-wing thinkers in the Labour Party and often found himself at odds with the leaders of the party and the other more moderate members. He set out his ideas in a book called Arguments for Socialism, published in 1979. In his view Britain's consensus-based, Keynesian, managed welfare-state economy had collapsed. The “democratic socialism” that he offered would involve a large measure of public investment, public expenditure, and public ownership combined with self-management in the workplace. Benn also argued for Britain's withdrawal from Northern Ireland, from the North Atlantic Treaty Organization, and from the European Union. In the 1990s he was a lively critic of “New Labour.” In 2001 Benn retired from Parliament.