The Scream 4 star will play teen heroine Lena Holoway in an adaptation of Lauren Oliver's novel series, TVLine reports.
Delirium - from Prison Break producer Karyn Usher - is set in a future world where all feelings of love have been eradicated. Roberts's character rebels against the system when she falls for a young man.
22-year-old Roberts - the niece of Julia Roberts - first rose to fame for her role in the Nickelodeon television series Unfabulous. Her recent credits include the films Hotel for Dogs (2009), The Art of Getting By (2011) and Celeste and Jesse Forever (2012).
The Delirium pilot was picked up by Fox last month, alongside a new television version of Sleepy Hollow from Star Trek Into Darkness writers Alex Kurtzman and Roberto Orci.
Other pilots in contention for a series pick-up at the network include Gavin & Stacey US remake Friends & Family and the legal drama Rake starring Greg Kinnear.
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Watch Emma Roberts in the trailer for Scream 4 below: