was born in Yorkshire to parents who performed as a country and western duo which she soon became involved in: dancing from the age of 4 and singing with her parents when she was about 7. At 14 she made her professional debut in Annie playing the lead role.
Sheridan made her West End debut as Tallulah in the National Youth Music Theatre production of Bugsy Malone. Since then she has appeared as Little Red Riding Hood in the Donmar Warehouse production of Into the Woods, Ancient Lights for Hampstead Theatre; The People are Friendly for the Royal Court and Tinderbox at The Bush Theatre.
She made her Shakespearean debut at the Open Air Theatre in Regent's Park playing Hermia in A Midsummer Night's Dream and Bianca in The Taming of the Shrew. She also played the lead role of Audrey in the Menier Chocolate Factory's production of Little Shop of Horrors, which subsequently transferred to the West End.
Sheridan's first TV appearance was in 1999 when she played Matilda in ITV's Dark Ages. Since then she has appeared in many award-winning television roles which include eight series of Two Pints of Lager and a Packet of Crisps; two series of Grown Ups (written specifically for her); two series of Love Soup and four series of Benidorm.
She played Emma in the multi award-winning The Royle Family and appeared as a guest lead in Gavin and Stacey. Her other television credits include Blood Strangers; Doctors; The Royal; Hawk; Fat Friends and The Comic Strip Presents Sex Actually; as well as Lark Rise to Candleford and sidekick to Jonathan Creek.She also played Lucie Miller, the Doctor's assistant, in the radio version of Dr Who.
Sheridan played the lead Elle Woods in the musical version of Legally Blonde in at the Savoy Theatre for which she won the 2011 Olivier Award for Best Actress in a Musical.
Her last appearance in London's West End was in Trevor Nunn's production of Terence Rattigan's Flare Path at the Haymarket Theatre.
She recently appeared on the West End stage for a limited season at the Old Vic playing Hedda Gabler: a role which has been described as the female version of Hamlet.
In September she is starring as Titania alongside David Walliams as Bottom in Shakespeare's A Midsummer Night's Dream as part of the new Michael Grandage Company season the Noel Coward Theatre.