Samuels, who will play the role through to 22 January 2011, takes over from fellow TV casting graduate Siobhan Dillon, a contestant on How Do You Solve a Problem Like Maria?.
In a press statement, Samuels said she is "unbelievably excited" to be joining the cast. "It was one of the first musicals I was taken to see as a young child and so to be given the opportunity to recreate the iconic role of Sandy and to make my West End debut in the show, is a dream come true."
Other Over the Rainbow contestants to have been cast since the show finished in May include semi-finalist Steph Fearon, who'll appear in a forthcoming fringe revival of Smokey Joe's Cafe (See News, 8 Jun 2010). The winner, Danielle Hope, will play Dorothy in Andrew Lloyd Webber's production of The Wizard of Oz, which opens at the Palladium next year.
Grease celebrates its third birthday in London this summer, having returned to the West End on 8 August 2007 (previews from 25 July). It's directed by David Gilmore, choreographed by Arlene Phillips, and produced by David Ian and Paul Nicholas, by arrangement with Robert Stigwood.