His family moved frequently every few years due to his father's work commitments, living in Chicago, Edmonton, Dublin, Ottawa, Montreal, New York settling eventually in Toronto, Ontario where he attended Lawrence Park Collegiate Institute.

[2] He trained there three years under the guidance of Pierre Lefebvre, Perry Schneiderman, Brigit Panet, Dame Peggy Ashcroft, George F. Walker, and Robert Lepage.

Power had his professional theatrical debut playing Demetrius in Joe Dowling's adaptation of Shakespeare’s A Midsummer Night's Dream on the mainstage of the Stratford Festival in Canada, acting alongside fellow NTSC alumni, Colm Feore.

[7] The play Stuck brought Power to HERE theatre in New York where he soon moved to the Lower East Side and subsequently developed a solid working relationship with Ellen Stewart of La MaMa.

The cast included musicians Bemshi Shearer (as Lady Day), bass player Theo Wilson (son of Billie's piano player Teddy Wilson), Jeremy Pelt on Trumpet, Ed Swanston (ex- piano for Louis Armstrong), Kalil Madi (ex-drummer for Billie Holiday) and Michael 'Smallchange' Johnson(Lemon Bucket), who was also musical director.

In 2015, Power returned to the West End to perform juror 7 with Tom Conti, Robert Vaughn and Jeff Fahey in Bill Kenright's production of Twelve Angry Men at the Garrick Theatre.

Lead Balloon, initially started on BBC4 and then moved to BBC2 where it ran from 2006–2011, with Power playing Marty, the sardonic writing partner of failed comedian Rick Spleen (Jack Dee).

[13] During this time Power also had guest leads on the British television series Moving Wallpaper, Holby City, Doctors, Taking the Flak, and Wild West.

[20] In late 2012, Power starred alongside Ryan Sampson, Kate Miles and Diane Morgan as Colby Brown in the mock reality/hidden camera show E4's The Work Experience.

Following The Rezort, Power was cast as a lead role alongside actors Billy Boyd, Alice Lowe, and Eline Powell in the Lennox Brothers debut feature Stoner Express (a.k.a.

In 2019, Sean teamed up with Irish production company Wytao Film's William Morgan and Vincent Walsh to shoot the award winning comedy Double Denim.