The Crown is seeking young actors with “a strong physical resemblance” to the Dukes of Cambridge and Sussex to play the princes in the final series of the Netflix drama.
A casting call notice for the show says it is seeking “two exceptional young actors” to portray William aged 16-21 and Harry aged 16-20.
The notice adds these will be “significant roles” in the lavish series.
It reveals shooting for the final episodes of the show will commence in late August in the UK, adding: “No previous professional acting experience required.
“We are very experienced in providing a great deal of support for the young actors and their families through what they find is a uniquely rewarding creative process.”
The show is expected to return for its fifth series later this year, with a new cast taking over.
Screen veteran Imelda Staunton will replace Olivia Colman as the Queen as the drama moves into the 1990s, and Lesley Manville will portray Princess Margaret.
Elizabeth Debicki moves into the role of Diana, Princess of Wales vacated by Emma Corrin.
The series will reportedly dramatise her headline-making 1995 Panorama interview with Martin Bashir as well as other key events in her later life.
Writer Peter Morgan has previously confirmed the sixth series will be the last.