The 10-year-old, who stars as Ben Brockman in the sitcom Outnumbered, has been cast as William Brown in the television adaptation of the Richmal Crompton story, reports the Daily Mail.
Just William producer John Chapman said: "It's not an accident that Daniel Roche's Ben is regarded as the Just William of today."
Brown's nemesis, Violet Elizabeth-Bott, will be played by Isabella Blake-Thomas, best known for starring in Green Balloon Club on CBeebies.
The series, which begins shooting later this month, will reportedly consist of four half-hour episodes shown in the run-up to Christmas.
It will be penned by Men Behaving Badly's Simon Nye, who most recently wrote Doctor Who episode 'Amy's Choice'.