Simon Arthur, 4th Baron Glenarthur

Major The Rt. Hon. Simon Mark Arthur, 4th Baron Glenarthur, DL (born 7 October 1944), is a British peer, pilot and businessman. Having succeeded to his father's titles in 1976, he is one of the ninety hereditary peers elected to remain in the House of Lords after the House of Lords Act 1999, and sits as a Conservative.

The son of The 3rd Baron Glenarthur, he was born into a Scottish mercantile family and was educated at Eton College. Commissioned to the 10th Royal Hussars in 1963, Glenarthur was Aide-de-Camp to the High Commissioner of Aden in 1964 and 1965. Between 1976 and 1980, he served as a Major in The Royal Hussars, Territorial and Army Volunteer Reserve, and was Captain for British Airways Helicopters between 1976 and 1982.

Lord Glenarthur served in the government of Margaret Thatcher in the House of Lords, and in 1982 became a Lord-in-Waiting (Government Whip) and became Parliamentary Under Secretary of State at the Department of Health and Social Security (DHSS) in 1983. He then moved to the Home Office before being promoted to Minister of State for Scotland in 1986. His last ministerial appointment was as Minister of State for Foreign and Commonwealth Affairs from 1987 to 1989. Amongst his particular responsibilities were Hong Kong and the United Kingdom's relationship with China.