Born in Inverness, he studied law at the University of Glasgow and Christ's College, Cambridge. He taught law at the London School of Economics and was called to the bar in 1967. He became a QC in 1978 and head of chambers in 1981. Among his pupil barristers were Tony Blair and Cherie Booth, and he dubbed himself "Cupid QC" for having introduced them. During the 1980s he also became a Recorder, and then a Deputy High Court Judge.
He remained Blair's confidant and advisor after Blair's election to parliament in 1983, and his appointment as Lord Chancellor after Blair's election victory in 1997 was widely expected. In addition to his traditional role of supervising the legal system, in 2001 he gained responsibility for a wide range of constitutional issues including human rights and freedom of information.
Irvine is not generally regarded as a natural politician - he has never stood for elected office - and has occasionally faced unwanted controversy as Lord Chancellor. Soon after taking the job he had his official residence in the Palace of Westminster redecorated at a cost to the taxpayer of over half a million pounds, with hand-printed wallpaper accounting for £59,000 of that. In 2003 he was awarded a pay rise of £22,691 as a result of a formula designed to keep his salary ahead of that of the Lord Chief Justice. After an outcry he accepted a more modest rise.