Bananarama, Sonia, Sinitta and a host of other Stock Aitken Waterman acts will appear at the concert to mark the label's 25th anniversary.
The reunion concert will take place at London's Hyde Park on July 11. The event's organisers have described it as a "celebration of the hit single".
They have also announced that a "very special duet" that was last performed 23 years ago will be part of the gig - which is presumed to be Kylie Minogue and Jason Donovan's 'Especially for You'.
Pepsi & Shirlie, Brother Beyond, Dead or Alive, Princess, Hazell Dean, Sybil, Lonnie Gordon and 2 Unlimited will also perform.
Pete Waterman said of the gig: "I've been saying no for years to a Hit Factory concert but now, 25 years on, the timing feels right."
Ticket sales will be donated to Cancer Research UK. Further acts are expected to be announced shortly.
Steps will return for a second Reunion series on Sky Living later this year.
> Pete Waterman attacks "snobbish" music industry
Watch the video for Kylie and Jason's 'Especially for You' below: