Arthur Brian Deane Faulkner, Baron Faulkner of Downpatrick, PC (18 February 1921 – 3 March 1977), was the sixth and last Prime Minister of Northern Ireland, from March 1971 until his resignation in March 1972. He was also the chief executive of the short-lived Northern Ireland Executive during the first half of 1974.

Faulkner was also the leader of the Ulster Unionist Party (UUP) from 1971 to 1974.

Faulkner was born in Helen's Bay, County Down, Ireland, two months before the creation of Northern Ireland. The elder of two sons of James and Nora Faulkner. His younger brother was Colonel Sir Dennis Faulkner, CBE VRD UD DL. James Faulkner owned the Belfast Collar Company which traded under the name Faulat. At that time, Faulat was the largest single-purpose shirt manufacturer in the world, employing some 3,000 people.

Brian Faulkner was educated initially at Elm Park preparatory school, Killylea, County Armagh, but at 14 was sent to the Church of Ireland-affiliated St Columba's College at Rathfarnham in Dublin, although Faulkner was Presbyterian. Faulkner chose St Columba's, preferring to stay in Ireland rather than go to school in England. His best friend at the school was Michael Yeats, son of W. B. Yeats. He was the only prime minister of Northern Ireland to have been educated in the Irish Free State and one of only two to have been educated in Ireland.

Faulkner entered the Queen's University of Belfast in 1939 to study law but, with the advent of World War II, he quit his studies to work full-time in the family shirt-making business.

Faulkner became involved in unionist politics, the first of his family to do so, and was elected to the Parliament of Northern Ireland as the Ulster Unionist Party Member of Parliament (MP) for the constituency of East Down in 1949. His vociferous traditional unionist approach to politics ensured him a prominent backbench position. He was, at the time, the youngest ever MP in the Northern Irish Parliament. He was also the first Chairman of the Ulster Young Unionist Council in 1949.

In 1956 Faulkner was offered and accepted the job of Parliamentary Secretary to the Ministry of Finance, or Government Chief Whip.

In 1959, he became Minister of Home Affairs and his handling of security for most of the Irish Republican Army's Border Campaign of 1956–62 bolstered his reputation in the eyes of the right wing of Ulster unionism.^{[citation needed]}