The show will focus on West Beverly Hills High School - the subject of the 1990s original - and the Mills family. Grimes, a Canadian, will play teenage daughter Annie Mills, who attends the school.
Lori Loughlin (Summerland) has also joined the production to play Celia Mills, the mother and an ex-Olympic cycling medalist.
A pilot created by Rob Thomas is in production for The CW. Because he is too busy, is now being written by What About Brian pair Gabe Sachs and Jeff Judah.
Stars rumoured to be involved include Hilary Duff and Jennie Garth, while Tori Spelling said she would "love" to take part.
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