Donough Edward Foster O'Brien, 16th Baron Inchiquin (5 January 1897 – 19 October 1968) was an Irish peer and 29th direct descendant of Brian Boru.

Inchiquin was Aid-de-Camp to the Viceroy of India and his future father-in-law, Frederic Thesiger, 1st Viscount Chelmsford, between 1919 and 1920.

Together they had two daughters: Inchiquin inherited the family Dromoland Castle estate in Ireland and Moor Park near Ludlow, Shropshire.

In 1962 Inchiquin finally gave in to the financial strain and sold the Dromoland Castle and 350 acres (1.4 km2) of its estate to billionaire industrialist Bernard McDonough and built himself nearby Thomond House, which he moved into in 1965 and a house that the current Baron Inchiquin resides in.

[10] The ancestral seat today serves as a luxury hotel and continues to be owned by a series of Irish American businessmen.