He was educated at Westminster School and King"s College, Cambridge and served with the Intelligence Corps in World World War World War II
When elected, he was the youngest Labour Member of Parliament. He lost his seat at the 1950 general election, but returned to Parliament at the 1955 election as Member of Parliament for Swindon. He resigned his seat in March 1969, by taking the Chiltern Hundreds. In 1971 he left the Labour Party in response to the party"s opposition to British membership of the European Economic Community.
He later joined the Social Democratic Party and later still the Conservative Party.
In 1948, Francis acted covertly for the British Government inside Franco"s Fascist Spain. His report "Spanish Summary" with a forward written by Lady Megan Lloyd George Member of Parliament had a huge influence in shaming the British and other governments and world-wide organisations for allowing the fascist state to remain undefeated in Europe until Franco"s death.
While he was an Member of Parliament Noel-Baker advocated reforms to moderate the influence of outside interests in Parliament. In 1961 he published an article in Parliamentary Affairs warning that "the door, in fact, is wide open for a new form of political corruption, and there is an uneasy feeling in Parliament and outside that its extent could be much greater than the known or published facts reveal".
38th United Kingdom Parliament. 41st United Kingdom Parliament. 42nd United Kingdom Parliament.
43rd United Kingdom Parliament.
44th United Kingdom Parliament]
He was first elected to the House of Commons in the Labour landslide at the 1945 general election as Member of Parliament for Brentford and Chiswick. Before his death in 2009 Noel-Baker was one of the few surviving members of the 1945 Parliament, the others being Michael Foot and John Freeman.