The two-hour concert takes place on a special stage at the Pier Head on August bank holiday Monday.
Today's signings follow festival appearances already announced by Buzzcocks, the Stranglers and Merseyside group Amsterdam, also appearing at the Pier Head on the Sunday, August 28.
James Bourne from Busted, Lee Ryan from Blue and Rachel Stevens from S Club 7 will all have their own slots, produced by Radio City in partnership with Liverpool's Capital of Culture company.
Tickets will be distributed on a first-come basis at HMV shops in Liverpool, Birkenhead, Warrington and Southport.
More than £350,000 is being spent giving the three-day Mathew Street Festival a makeover.