Basil Stanlake Brooke, 1st Viscount Brookeborough, KG, CBE, MC, TD, PC, styled Sir Basil Brooke, 5th Baronet between 1907 and 1952, was an Ulster Unionist Party politician who became the third Prime Minister of Northern Ireland in May 1943, holding office until March 1963.
Lord Brookeborough had previously held several ministerial positions in the Government of Northern Ireland, and has been described as "perhaps the last Unionist leader to command respect, loyalty and affection across the social and political spectrum of the movement". He has also been described as one of the most hardline anti-Catholic leaders of the UUP.