They join existing cast members Alex Gaumond (Galileo), Kevin Kennedy (Pop), Brenda Edwards (Killer Queen) and Rachel John (Meat).
Samuels was a finalist in BBC TV's "Over the Rainbow" contest to play Dorothy in The Wizard of Oz. She will play Scaramouche, whom press materials describe as "a rock-chick-with-an-attitude."
Harvey has previously appeared at the Dominion Theatre as the original Beast in Disney's Beauty and the Beast, and has also appeared in the West End in The Phantom of the Opera, Side By Side By Sondheim, Sunday in the Park With George and Les Miserables. His TV appearances include "EastEnders," in which he played Jane Beale's love interest Martin. He will play the Killer Queen's side kick Khashoggi.
Robinson, who will take over the role of the fast-fisted and brave-hearted rebel Britney, has previously performed the same role in the U.K. national tour of the show. Other credits include Hairspray and The Lion King in the West End, and touring in The Magic of Motown. He is also a successful solo recording artist who has written and performed alongside such artists as Lulu and Lionel Richie.
To book tickets, on sale through October 2012, contact the box office on 0870 169 0116, or visit www.wewillrockyou.co.uk