He was educated at Eton and Balliol College, Oxford where he was president of the Oxford Union, and thereafter at the University of Edinburgh.
He served as an advocate and an interim Procurator Fiscal Depute from 1968 to 1972. From 1972 to 1974, he was a councillor on Edinburgh District Council, and after unsuccessfully contesting Hamilton in February 1974, from October 1974 to 1997 he was Member of Parliament for Edinburgh West. During this time he served in the Scottish Office.
In the years between 1987 and 1995 he served as Parliamentary Under-Secretary of State for Scotland, and thereafter as Minister of State between 1995 and 1997. He had previously been a Lord Commissioner of the Treasury between 1979 and 1981. He was appointed a Privy Counsellor and Queen's Counsel in 1996.
It was announced on 12 December 2011 that he would serve as Lord High Commissioner to the General Assembly of the Church of Scotland, who is the Sovereign’s personal representative to the Annual General Assembly of the Church of Scotland, in 2012.
In 1994 on the death of George Nigel Douglas-Hamilton, 10th Earl of Selkirk, Selkirk inherited the earldom, although the succession was disputed, as Alasdair Douglas-Hamilton, a nephew of the 10th Earl, claimed it, ultimately without success. Due to the terms of the Peerage Act 1963, Selkirk was considered to be unable to vote in the House of Commons until he had disclaimed the title, even though the succession to it had not been decided. As the Conservative government of the day had a small majority, he felt obliged to disclaim immediately.
In 1997, he was elevated to the House of Lords as a life peer, being created Baron Selkirk of Douglas, of Cramond in the City of Edinburgh.
From 1999 to 2007 he was a member of the Scottish Parliament and was deputy Convener of its Education Committee. In November 2005, Lord Selkirk of Douglas announced his intention to retire at the end of the 2003-2007 session of the Scottish Parliament. He continues to sit in the House of Lords, taking a particular interest in British legislation as it affects Scotland.
Lord Selkirk of Douglas has written a number of books, including Motive For a Mission: The Story Behind Hess's Flight to Britain about his father's meeting with Rudolf Hess when he landed in Scotland during World War II.1942–1974: Lord James Douglas-Hamilton
1974–1996: Lord James Douglas-Hamilton
1994: The Rt Hon. The Earl of Selkirk
1994–1996: Lord James Douglas-Hamilton
1996–1997: The Rt Hon. Lord James Douglas-Hamilton
1997: The Rt Hon. Lord James Douglas-Hamilton
1997–1999: The Rt Hon. The Lord Selkirk of Douglas
1999–2007: The Rt Hon. The Lord Selkirk of Douglas
2007–: The Rt Hon. The Lord Selkirk of Douglas
In 1974 he married the Hon. (Priscilla) Susan Buchan, a granddaughter of the politician and novelist John Buchan, and daughter of Johnnie Buchan, the 2nd Baron Tweedsmuir, and his wife, a life peeress in her own right, Lady Tweedsmuir. They have four sons of whom the eldest, John Andrew Douglas-Hamilton, Lord Daer and Master of Selkirk (b 1978) is heir apparent to the disclaimed Earldom of Selkirk. Lord Selkirk of Douglas is also fifth in line to the Dukedom of Hamilton, after the sons and the brother of the present duke.