Born in Harpurhey, Wilkinson attended North Manchester High for Boys before taking various jobs such as a relief pub landlord and the coach of a football team in Toronto. In 1995, he tried stand-up comedy for the first time at The Frog And Bucket comedy club, adopting the stage name "Smug Roberts"; the "smug" came from an event in his life where people teased him for being a "smug bastard" and the "Roberts" was adapted from his middle name. Caroline Aherne and her then-husband Peter Hook watched his set and she put him in contact with an agent.
Six weeks later, Roberts performed his first one-man gig. In 1998, he released the novelty anthem "Meat Pie, Sausage Roll (Come on England, Gi's a Goal)" as "Grandad Roberts", a character from his afternoon radio show on Key 103. In 2000, he headlined with Paul Merton and John Thomson at the opening night of the Manchester Comedy Store. His appearance there lead to a role in the film 24 Hour Party People (2002). Roberts has also appeared on television, with recurring roles in Cutting It and Buried. He has appeared in every television production by Peter Kay, except for Max and Paddy's Road to Nowhere, and is due to appear in Kay's new production, Britain's Got The Pop Factor....
In 2006, he performed Me Dad's Dead, a one-man play about the death of his father, at the Edinburgh Festival. In 2008, he became the first stand-up comedian to perform at the Erin Arts Centre on the Isle of Man. A local critic praised his style of anecdotal humour.
Roberts has two sons and one daughter.