Alan Henry Brooke, 3rd Viscount Brookeborough (born 30 June 1952), is a Northern Irish peer and landowner. He is one of the 92 hereditary peers who remain, for life, in the House of Lords, and is the current Lord Lieutenant of Fermanagh, sitting as a crossbencher.
Lord Brookeborough was educated at Harrow School, Millfield, and the Royal Agricultural College, 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 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. The centre of the estate is Colebrooke Park, an early 19th-century neo-Classical country house that is the ancestral seat of the Brooke family.