Séainín has tread the boards of some of the most prestigious theatres and her performances have won her rave reviews across Ireland and the UK, most notably for creating the role of Regine in the World Premiere of Ibsen's GHOSTS by Frank McGuinness at Bristol Old Vic and for her portrayal as Helen Woods in the Irish Premiere of SCENES FROM THE BIG PICTURE by Owen McCafferty, directed by Conal Morisson.

No stranger to the Dublin stage, Séainín worked with the Award Winning Broadway director David Esbjornson in Arthur Miller's DEATH OF A SALESMAN, in a sell out run at The Gate Theatre.

She created the role of Rebecca Loos in the World Premiere of MACBECKS, the smash hit comedy about David Beckham at the Olympia Theatre and most recently work-shopped the new play God's Hotel at The Abbey Theatre (Ireland's National Theatre), under the direction of David Horan.

A selection of Séainín's Theatre Credits: God's Hotel [Abbey Theatre, Dublin]; Death of a Salesman [Gate Theatre, Dublin]; Macbecks [Olympia Theatre, Dublin]; Scenes from the Big Picture* [Prime Cut Productions]; Ghosts [Bristol Old Vic]; Excellent Beauty [Union Theatre, London]; The Pied Piper, Aladdin [Dubbeljoint Theatre Company]; Other Women [Bridewell & Greenwich Theatres, London]; Aspects of Love [Electric Theatre, Guildford]; West Side Story [UK Tour].