Darren will join the previously announced cast of Faye Brookes, Sinitta, Divina De Campo, Dialenga Scott and Joel Montague.
Other cast members will include Ishmail Aaron, Michelle Andrews, Gabby Antrobus, Delycia Belgrave, Joel Benjamin, Tanisha-Mae Brown, Emily Goodenough, Billie Hardy, Aaron Jenkins, Liam Marcellino, Theo Reece, Hollie Jane Stephens and Harrison Wade.
Darren Day has previously appeared in the West End in the title role in Joseph and his Amazing Technicolor Dreamcoat and has many other credits such as Danny Zuko in Grease at the Cambridge Theatre.
He was also a contestant on the very first series of I'm a Celebrity Get Me Out of Here! and a finalist on Celebrity Big Brother.
Faye Brookes, who plays Roxie Hart, recently reached the final of this year’s series of ITV’s Dancing on Ice and is best known for her role as Kate Connor in ITV''s Coronation Street.
Sinitta is an international recording artist having released 15 hit pop records including So Macho, Toyboy and Cross My Broken Heart.
She has also apperared in West End productions of Cats, Little Shop of Horrors, Hair and Smokey Joe's Cafe.
Sinitta has als remaned in the spotlight becoming a mentor to young emerging talent as Simon Cowell's right-hand woman on the X-Factor.
Davina De Campo is a seasoned British drag queen and singer who was recently crowned runner-up on the first series of RuPaul's Drag Race UK.
Set amid the razzle-dazzle decadence of the 1920s, Chicago tells the story of Roxie Hart, a housewife and nightclub dancer who murders her on-the-side lover after he threatens to walk out.
Desperate to avoid conviction, she dupes the public, the media and her rival cell-mate, Velma Kelly, by hiring Chicago’s slickest criminal lawyer to transform her malicious crime into a barrage of sensational headlines, the likes of which might just as easily be ripped from today's tabloids.
Since it opened in New York in 1996, Chicago has played in 36 countries worldwide and has been seen by an estimated 33 million people and is the longest running American musical in Broadway and West End history.