Donough O'Brien, 16th Baron Inchiquin

Donough Edward Foster O'Brien, 16th Baron Inchiquin (5 January 1897 – 19 October 1968) was the holder of a hereditary peerage in the Peerage of Ireland, as well as Chief of the Name of O'Brien and Prince of Thomond in the Gaelic Irish nobility.

Biography
The first of five children born to Lucius O'Brien, 15th Baron Inchiquin, and Ethel Foster, and older brother of Phaedrig O'Brien, 17th Baron Inchiquin, he was also the uncle of the current incumbent, Conor O'Brien, 18th Baron Inchiquin. He was educated at Eton College, the Royal Military College, Sandhurst, early in the First World War, and Magdalen College, Oxford.

He married, on 13 December 1921 Anne Molyneux Thesiger (1898-1973), daughter of Frederic Thesiger, 1st Viscount Chelmsford.

O'Brien was commissioned into the British Army's Rifle Brigade in 1916 and served with their 3rd Battalion in the First World War. He was ADC to the then Viceroy of India – his future father-in-law – from 1919 to 1920 and left the regular army in 1921. He held the Order of the Crown (Romania).

He served in the Second World War from 1939 to 1942 as a Captain in the London Rifle Brigade, a Territorial regiment.

Inchiquin inherited the family Dromoland Castle estate in Ireland and Moor Park near Ludlow, Shropshire. He moved home permanently to Ireland in 1939. He sold Dromoland Castle and 350 acre of its estate because of financial difficulties and built himself nearby Thomond House, into which he moved in 1965. He died in 1968 aged seventy-one and was succeeded in the peerage by his younger brother, Phaedrig.