Darren Day auditioned for BBC's talent show Opportunity Knocks in 1987 and appeared on the show in 1988, introduced by host Bob Monkhouse as the new Bobby Davro.
After five years with a career that spanned being a Butlins redcoat, doing stand-up comedy, and singing with bands, Day made his breakthrough as a singer and dancer in London's West End theatre, starring in Joseph and the Amazing Technicolor Dreamcoat, replacing the departing Phillip Schofield. He then developed his career as a television presenter and has presented programmes such as You Bet!, and Don't Try This at Home! He appeared in the first series of the reality television show I'm a Celebrity... Get Me Out of Here! He finished third.
Day has appeared in many touring stage musicals, including Summer Holiday, Grease, The Rocky Horror Show, and Hellbreeder. In the Pantomime season of 2005/06, Day appeared in the Derby Assembly Rooms production of Cinderella, where he played the part of Buttons. This is also were he first met his wife Stephanie, as she was appearing in the production.
Day worked in November 2006 on the Celebrity Scissorhands project for the BBC in aid of Children in Need. From there, he returned to pantomime for the 2006/07 season as 'Jack' in Jack and the Beanstalk at the Billingham Forum Theatre.
In 2007, Day toured the UK with a brand new theatre show The Music of Manilow and More, and made a guest appearance in July on ITV's police drama The Bill, playing a photographer who is the prime suspect in the death of a supermodel.
Autumn 2007 saw him take over from Mark Little in the UK tour of Defending the Caveman before returning to pantomime at The Lowry, Salford as King Rat in Dick Whittington co starring his wife and actress Stephanie Dooley, and Chesney Hawkes.