The 20-year-old will feature in the show's Newcastle dates at the Metro Radio Arena on May 29 and May 30. He will be singing the musical's finale number 'Ghost - Take My Hand'.
McElderry commented: "I'm such a huge fan of Coronation Street - it's been a huge part of my life since I was a child, so to be a part of this amazing musical homage is really exciting.
"I can't wait to be stood on stage in my home town alongside the cast of Corrie singing this beautiful finale number. It's an honour."
Street of Dreams has its world premiere in Manchester on May 9 and later tours the UK and Ireland.
Paul O'Grady, Julie Goodyear, Kevin Kennedy, Brian Capron, Bill Roache, Katy Cavanagh, Kym Marsh and Jodie Prenger are among the cast confirmed for the project.
> Coronation Street musical to tour in May
> Coronation Street musical casts Kym Marsh as Elsie Tanner
> Jodie Prenger interview: 'Corrie musical role is so exciting'
> Read more Coronation Street news and spoilers
Watch a promo for Coronation Street's Street of Dreams musical below: