Séainín trained at the Guildford School of Acting (GSA) and the Irish Film Actors Studio.

Séainín made her professional stage debut in Peter Pan and The Mikado at The Lyric Theatre, Belfast. For the next six years she trained at the Lyric Drama Studio under some of Northern Ireland's leading practitioners.

She subsequently won leading child roles in the West End tours of The Sound of Music and Joseph at the Grand Opera House and was later chosen to sing solo at the Gala Concert EducAid at the Piccadilly Theatre in London's West End.

Already a familiar face, Séainín was then asked to present the cult BBC TV show Why Don't You? This led to Séainín winning the title of Young Champion for outstanding contributions to the Arts. She was next to be seen as Rosalia in the UK and Irish tour of West Side Story before taking up her place at GSA.

While at GSA, Séainín played numerous lead roles, which culminated in her performance as Guilietta Trapani in Aspects of Love.

Back in Ireland, She quickly became known as "our favourite once-upon-a-time character" for her memorable performances as Snow White in Snow White and the Seven Dwarves and Goldilocks in Goldilocks and the Three Bears at the Waterfront Concert Hall and for her portrayal of Lotus Blossom in Aladdin and Toffee Jenkins in The Pied Piper for Dubbeljoint Theatre Company, under the direction of Pam Brighton.

In London, Séainín won rave reviews in Excellent Beauty playing Fanny at the Union Theatre.
Séainín went on to create the lead role of Mary in the arena spectacular The Magical Rhythms of Ireland, directed by the award winning Dutch Director Jeroen Cardoso Lopez. Carol Medcalfe then asked Séainín to perform at the Bridewell 10th Anniversary Gala Concerts, directed by Matt Ryan to mark the closing of the theatre.

2007 saw Séainín play Regine in Ibsen’s Ghosts, a new version and World Premiere by Frank McGuinness at Bristol Old Vic. Séainín received exceptional reviews for her performance in this gritty, fresh and shocking new version.

When Ghosts ended, she started rehearsals for the Irish Premiere of Owen McCafferty’s Scenes from the Big Picture playing Helen Woods, under the direction ofConall Morrisson.

Scenes from the Big Picture received an Irish Times Theatre Nomination for BEST PRODUCTION at the Irish Times Theatre Awards in February 2008.

Next month, Séainín will create the role of Rebecca Loos in the eagerly awaited new musical comedy Macbecks at the Olympia Theatre, Dublin. A new piece for Long Road Productions directed by David Bolger.
The show will open in January 2009.

Read about Séainín's TV and Film credits.