Colonel Evan Henry Llewellyn (25 February 1847 – 27 February 1914) was a British Army officer and a Conservative politician who sat in the House of Commons between 1885 and 1906.
Llewellyn was the fourth son of Llewellyn Llewellyn of Buckland Filleigh, North Devon. He was educated at Rugby School. He was a J.P. and Deputy Lieutenant of Somerset. He served in the British Army and was the commander of the 2nd (Central African) Battalion, King's African Rifles.
In the 1885 general election, Llewellyn was elected as Member of Parliament (MP) for North Somerset and held the seat until the 1892 general election. He was re-elected for the seat in the 1895 general election and held it until the 1906 general election.
Llewellyn lived at Langford Court, Somerset. His son Hoel served with distinction in the Anglo-Boer War. He is the great-great-grandfather of David Cameron, who was Prime Minister of the United Kingdom from 2010 to 2016.