Reid was educated in Coatbridge, before attending the University of Stirling, receiving a bachelor's degree in history and a Ph.d in economic history. After graduation he worked as a research officer for the Labour Party and as a trade union organiser. He entered parliament in 1987 as MP for the Motherwell North constituency (later renamed as Hamilton North and Bellshill).
Reid is a senior member of the Labour Party, and has held several different Cabinet positions: Secretary of State for Scotland, Secretary of State for Northern Ireland (the first Catholic to hold the position), Minister Without Portfolio (Labour Party Chairman), Leader of the House of Commons and Lord President of the Council. On June 12, 2003 he was appointed Health Secretary following the resignation of Alan Milburn.
Reid, is a former member of the Communist Party (of which he has said: "I used to be a Communist. I used to believe in Santa Claus"). Reid has a reputation as a tough fighter, and a shrewd negotiator; he is also regarded as one of the most intelligent MPs in the House.
An MP since 1987, his seat is due to be abolished in boundary changes, but he is effectively guaranteed a new one. Reid is a Catholic, and there is much speculation that he will become MP for the predominantly Catholic and rock-solid Labour seat of Glasgow East, which will be created in the boundary changes.