James Henry Molyneaux, Baron Molyneaux of Killead, KBE, PC (27 August 1920 – 9 March 2015), often known as Jim Molyneaux, was a unionist politician from Northern Ireland who served as leader of the Ulster Unionist Party (UUP) from 1979 to 1995, and as the Member of Parliament (MP) for South Antrim from 1970 to 1983, and later Lagan Valley from 1983 to 1997. An Orangeman, he was also Sovereign Grand Master of the Royal Black Institution from 1971 to 1995, and a leading member of the Conservative Monday Club.

Born in Killead, a small village in County Antrim, to Sarah (née Gilmore) and William Molyneaux, James Molyneaux was educated at a nearby school in Aldergrove. Although he was a member of the Church of Ireland, he briefly attended a local Roman Catholic primary school.

Molyneaux served in the Royal Air Force between 1941 and 1946, including most of the Second World War. He took part in the liberation of the Bergen-Belsen concentration camp and occasionally gave interviews about what he saw there. On 1 April 1947, he was promoted to flying officer.

From 1964 until the 1970s, Molyneaux served on Antrim County Council,. At the 1970 general election he was elected to the House of Commons as UUP Member of Parliament (MP) for South Antrim, succeeding Sir Knox Cunningham, with whom he had worked closely as honorary secretary of the South Antrim Unionist Association.

South Antrim had one of the largest electorates of any parliamentary constituency, and it consistently returned Unionist MPs with large majorities. Cunningham's 1959 majority of 50,041 was the largest in the United Kingdom, achieved with 95.1% of the votes. Molyneaux won over 60% of the votes in each of the four elections he contested in South Antrim, and at the 1979 general election his 69.0% share of the votes gave him a majority of 38,868 votes, the largest in the United Kingdom.

Molyneaux's maiden speech, made on 15 February 1971, focused on the security situation in Northern Ireland at that time, and concluded: "The vast majority of people in Northern Ireland are keen to make their contribution to the greater unit of the United Kingdom, just as we, their representatives in this House, try to play our part. Collectively, Ulstermen and women will do what is asked of them, as they have done in the past, both in peace and in war."

In October 1974, Molyneaux became leader of the Ulster Unionists in the House of Commons. From 1982 to 1986, he sat as a UUP member for South Antrim in the Northern Ireland Assembly which was unable to deliver devolution at that time. Molyneaux was admitted to the Privy Council in 1982, and in October that year he survived two Irish National Liberation Army (INLA) assassination attempts.

With then UUP leader Harry West, Molyneaux had played a significant role in negotiations with James Callaghan's minority Labour government which led to Northern Ireland's representation in the Commons being increased from 12 to 17 seats, under the House of Commons (Redistribution of Seats) Act 1979. The extra seats were added for the 1983 general election, when the resulting boundary changes divided South Antrim, and Molyneaux was elected for the new seat of Lagan Valley.