Alan Henry Brooke, 3rd Viscount Brookeborough, KG, KStJ (born 30 June 1952), is a Northern Irish peer and landowner. He is one of the 92 hereditary peers who remain in the House of Lords; he sits as a crossbencher. He is the current Lord Lieutenant of Fermanagh.

Lord Brookeborough was educated at Harrow School, Millfield and at the Royal Agricultural College (now Royal Agricultural University), Cirencester.

He joined the British Army in 1971, being commissioned into the 17th/21st Lancers. In 1977 he transferred to the Ulster Defence Regiment (UDR), which was to become the Royal Irish Regiment (RIR) in 1992. He was promoted to lieutenant-colonel in 1993, and became honorary colonel of the 4th/5th Battalion, Royal Irish Rangers, in 1997.

Lord Brookeborough (known to his family and friends as Alan Brooke or Alan Brookeborough) married Janet Elizabeth Cooke (daughter of J. P. Cooke, of Doagh), now Viscountess Brookeborough, in 1980. They farm the 1,000 acres (4.0 km²) Colebrooke Estate, just outside Brookeborough in County Fermanagh, Northern Ireland.^[1] The centre of the estate is Colebrooke Park, an early 19th-century Neoclassical country house that is the ancestral seat of the Brooke family.

Lord Brookeborough has no children. His younger brother, The Hon Christopher Brooke (who has four sons), is heir presumptive to the viscountcy. Lord Brookeborough intends to leave the Colebrooke Estate, including Colebrooke Park, to his nephew, his brother's eldest son and heir. He is third cousin to Queen Camilla, both descending from the 1st Baron Ashcombe.^[2]

Field Marshal The 1st Viscount Alanbrooke (1883–1963) was also a member of the same family. Lord Alanbrooke was an uncle of the 1st Viscount Brookeborough.

Brooke succeeded his father as Viscount Brookeborough in 1987. Although he lost his automatic right to a seat in the House of Lords, with all other hereditary peers after the passage of the House of Lords Act 1999, Lord Brookeborough remained in the House as an elected crossbench hereditary peer.^[3]

He was a Lord-in-waiting to The Queen beginning in 1997. He is President of the Co Fermanagh Unionist Association and was appointed an independent member of the Northern Ireland Policing Board in 2001.^[4] Lord Brookeborough represented The Queen as Lord-in-Waiting at the arrival of U.S. President Barack Obama and First Lady Michelle Obama in the United Kingdom on their state visit on 24 May 2011.^[5]

	Knight Companion of the Order of the Garter (KG)	23 April 2018[6]
	Baronet	7th Baronet Brooke of Colebrooke
	Knight of the Order of St John (KStJ)	26 June 2014[7]
	General Service Medal	with clasp Northern Ireland
	Queen Elizabeth II Diamond Jubilee Medal	6 February 2012
	Queen Elizabeth II Platinum Jubilee Medal	6 February 2022
	King Charles III Coronation Medal	6 May 2023
	Accumulated Campaign Service Medal
	Sash of the Order of the Aztec Eagle	(Mexico, 9 September 2015)[8]
	Commander of the Order of Isabella the Catholic	(Spain, 12 July 2017)

• List of Northern Ireland members of the House of Lords