Sir Eustace Twisleton-Wykeham-Fiennes, 1st Baronet

Lieutenant-Colonel The Hon. Sir Eustace Edward Twisleton-Wykeham-Fiennes, 1st Baronet (29 February 1864–9 February 1943) was a British soldier, Liberal politician and colonial administrator.

Fiennes was the second son of the 17th Baron Saye and Sele and his wife, Lady Augusta Hay-Drummond, a daughter of the 11th Earl of Kinnoull.

He was commissioned into the Queen's Own Oxfordshire Hussars in 1895. He was promoted Lieutenant in 1899, Captain in 1901, Major in 1905, and Lieutenant-Colonel in 1918.

He fought in the North-West Rebellion in 1885, was stationed in Egypt from 1888-89, took part in the expedition to Mashonaland in 1890, and fought in the Second Boer War with the Imperial Yeomanry.

At the 1906 general election, Fiennes was elected as Member of Parliament (MP) for Banbury and with a brief interruption in 1910, held the seat until the 1918 general election. He was also Parliamentary Private Secretary to Winston Churchill, the then First Lord of the Admiralty from 1912-14 and fought in Flanders and the Dardanelles during World War I.

Created a baronet in 1916, Fiennes left the Commons two years later to become Governor of the Seychelles and was then Governor of the Leeward Islands from 1921-29. In 1894, he had married Florence Agnes Fletcher "née" Rathfelder (from Constantia, Cape Town) and they had two children: John Eustace (1895–1917, Battle of Arras) and Sir Ranulph Twisleton-Wykeham-Fiennes, 2nd Baronet (1902-1943). Fiennes died in 1943 and his title was inherited by his son who died the same year, the explorer Sir Ranulph Fiennes inherited the title on his birth in 1944.