Colonel Windham Henry Wyndham-Quin, 5th Earl of Dunraven and Mount-Earl CB DSO (7 February 1857 – 23 October 1952) was an Irish Peer, British Army officer and a Conservative Member of Parliament for South Glamorganshire 1895–1906.
Wyndham-Quin was a major in the 16th Lancers, and served in the First Boer War in 1881.
He again volunteered for service in South Africa in early 1900, during the Second Boer War, and was appointed a captain in the Imperial Yeomanry on 14 February 1900. He raised and commanded the 4th (Glamorgan) Company, IY, which left Liverpool on the SS Cymric in March 1900 to serve as a company of the 1st Battalion Imperial Yeomanry. On 18 April 1900 he was appointed 2nd in command of this battalion. He was mentioned in despatches, received the Queen's medal (3 clasps), and was awarded the Distinguished Service Order (DSO) in November 1900. On return from South Africa he raised and commanded the Glamorgan Imperial Yeomanry, a full regiment that perpetuated 4th Company. He was promoted to the honorary rank of colonel on 19 Oct 1901.
In the 1895 general election he was elected Member of Parliament for South Glamorganshire, winning the seat for the Conservative Party. He was re-elected in 1900, but lost the seat in the 1906 general election.
He served as High Sheriff of County Kilkenny for 1914.
See the 5th Earl of Dunraven