Irish humorist, 1911 - 1966.
Flann O'Brien, whose real name was Brian O'Nolan, wrote a column called Cruiskeen Lawn under the pseudonym Myles na Gopaleen for thirty years (1936 - 1966) in The Irish Times. Many of these columns have been reprinted in The Best of Myles, which I'm sorry to say didn't live up to my expectations.
O'Brien also wrote some novels, AFAIK the best known being At Swim-Two-Birds, which is, eh . . . hard to describe. It's about a student, and a bar, and most other things. It's not quite as straightforward as Ulysses, but it's a hoot. He was a helluva writer.
Other works: The Dalkey Archive, The Hard Life: An Exegesis of Squalor, The Third Policeman, An Béal Bocht (The Poor Mouth).