James Hillier
as Patrick
Ben Miles
as Peter Townsend
Matt Smith
as Philip, Duke of Edinburgh
Josh O'Connor
as Prince Charles
Tobias Menzies
as Prince Philip (older)
Emma Corrin
as Diana
Harry Hadden-Paton
as Martin Charteris
Greg Wise
as Lord Mountbatten
Jason Watkins
as Harold Wilson
Ben Daniels
as Lord Snowdon
Emerald Fennell
as Camilla Parker Bowles