Born in London as the second of three sons whose parents were a labourer in Morgan Crucible Factory in Battersea and a teaching assistant. His parents were Tories "who believed in character and pulling oneself up by one's own bootstraps". Field was educated at St Clement Danes School which was then located in Hammersmith, London, before studying economics at the University of Hull. In his youth, he was a member of the Conservative Party, but left due to his opposition to South Africa's apartheid system. In 1964, he became a further education teacher in Southwark and Hammersmith. Field served as a councillor in the London Borough of Hounslow from 1964—68. He was a Director of the Child Poverty Action Group 1969—79, and of the Low Pay Unit (a body that campaigned to ensure wages councils protected the rights of workers in certain industries) from 1974—80.

Field unsuccessfully contested the constituency of South Buckinghamshire at the 1966 General Election, where he was defeated by the sitting Conservative MP Ronald Bell. He was selected to contest the safe Labour seat of Birkenhead at the 1979 General Election on the retirement of the sitting MP Edmund Dell. Field held the seat with a majority of 5,909 and has remained the constituency's MP since then.

In Parliament, Field was made a member of the Opposition frontbench by the then Labour leader Michael Foot as a spokesman on education in 1980, but was dropped a year later. Following the appointment of Neil Kinnock as the Labour leader in 1983, Field was appointed as a spokesman on health and social security for a year. He was appointed the chairman of the social services select committee in 1987, becoming the chairman of the new social security select committee in 1990, a position he held until the 1997 election.

Two nights before the Conservative Party leadership election in November 1990, he visited then Prime Minister Margaret Thatcher at 10 Downing Street. He advised her that her time as Prime Minister was drawing to a close and that she should back John Major to take over the role. His reason for doing so was that he felt that her Conservative colleagues would not tell her straight that she could not win a leadership contest. Following this meeting, he was smuggled out of Downing Street's back door. Two days later Margaret Thatcher supported John Major for the post, and he went on to be Prime Minister.

Following the 1997 election, with Labour in power, Field joined the government of Tony Blair as the Minister of Welfare Reform at the Department of Social Security with the rank of Minister of State. He was also made a member of the Privy Council. Field viewed his task as "thinking the unthinkable" in terms of social security reform, however others report that the Prime Minister Blair wanted some simpler vote-winning policy ideas. There were clashes with the Chancellor of the Exchequer, Gordon Brown, and the Secretary of State for Social Security, Harriet Harman. Field resigned his ministerial position in 1998 rather than accept a move away from the Department of Social Security offered by Blair in a reshuffle. It was reported that Field had argued for Blair to promote him to Secretary of State for Social Security.

After holding office, he was a member of the ecclesiastical and public accounts committees. Since the 2005 General Election, he has remained on the backbenches. He was a vocal critic of the government from the backbenches, notably voting against Foundation Hospitals in November 2003. In May 2008, he was a significant critic of the abolition of the 10p tax rate and this led to Field describing Gordon Brown as "unhappy inside his own body". He later apologised in parliament for the personal attack. In June 2008, Field joined calls for the establishment of a devolved parliament for England.

On 8 June 2009, Field wrote on his internet blog that he believed that the Labour Party would not win the next election with Gordon Brown as leader. On 6 January 2010, Field was one of the few Labour leaders to back Geoff Hoon and Patricia Hewitt's calls for a secret ballot of the Parliamentary Labour Party in regards to the leadership of Gordon Brown. The ballot could have led to a leadership contest.

In May 2009 Field announced his candidacy for the Speaker of the House of Commons but later withdrew his candidacy citing lack of support from within his own party. John Bercow was eventually elected as the new speaker.

In the 2010 General Election Field retained his Birkenhead seat with an increased majority. He was given the role of "poverty czar" in David Cameron's coalition government - the first member of the Labour Party to have a role within Cameron's team.

Field's political stance has been somewhat at odds with the rest of the Parliamentary Labour Party in recent years. He is a member of the advisory board of the free-market think tank Reform, and of the new conservative magazine Standpoint. In May 2008, he said that Margaret Thatcher "is certainly a hero" and that "I still see Mrs T from time to time — I always call her 'Mrs T', when I talk to her." Although there have been attempts to get him to defect to the Conservatives, they have been without success. In 2008, Frank Field was named as the 100th most-influential right-winger in the United Kingdom by the Telegraph. Field supports the return of National service to tackle growing unemployment and instil “a sense of order and patriotism” in Britain’s young men and women. However, in May 2010, Field endorsed John McDonnell, the left-wing Chair of the Socialist Campaign Group and Labour Representation Committee, in the Labour leadership election to replace Gordon Brown.

Field believes strongly in fighting climate change. He co-founded the charity Cool Earth with Johan Eliasch. Cool Earth protects endangered rainforest and works with the local communities to combat climate change.

Field is a practising Anglican, and is chairman of the Churches Conservation Trust, and a member of the Church of England General Synod.