Liam O'Brien (born 11th January 1980 in Limerick,Ireland ) is an Irish actor who played Ethan Blake in Emmerdale from December 2003 to October 2006.
After his stint in Emmerdale, He joined the cast of Fair City as Paul Brennan's estranged brother Peter. In 2004, he appeared on Celebrity Stars in Their Eyes.
He worked and toured extensively with Limerick's Island Theatre Company with productions including Borrowed Robes, The Trickster, Our Town, The Taming of the Shrew, Mike Finn’s award-winning Pigtown and playing The Gentleman Caller in The Glass Menagerie. He also appeared in Walking Away. Dublin Theatre roles include Paris in Romeo and Juliet, Cary Grant in Come Up and See Me Sometime.
He played Dean Martin for over two years in the West End tour of The Rat Pack: Live From Las Vegas in the UK, Europe and US.
He also founded Bottom Dog Theatre company in his hometown of Limerick in 2009 and has produced fifteen shows to date - alternating between director, producer and actor in various productions. An acclaimed singer too, he has become one of Ireland's leading crooners in the style of heroes Tony Bennett and Frank Sinatra, and tours shows like his own Crooning at Christmas and big band performances throughout the UK, such as The Kings of Swing. He most recently performed the Irish premiere of Eric Bogosian's one man play Drinking In America, touring to eighteen venues across Ireland.