Pseudonym of Brian O'Nolan, aka Flann O'Brien. Under this name he wrote his Irish Times column, An Cruiskeen Lawn, as well as his Irish language novel, An Béal Bocht.

The name is taken from the clownish Irish character in Dion Boucicault's play The Shaughraun, and means "Myles of the Ponies".

The orthography "Myles na Gopaleen" comes from the original Boucicault play. However, in Irish language contexts, the writer preferred the mocking "Gaelic" orthography "Myles na gCopaleen", with the initial mutation shown. Actually, it should have been "Myles na gCapaillíní".