Main[]
- Imelda Staunton as Queen Elizabeth II
- Jonathan Pryce as Prince Philip
- Lesley Manville as Princess Margaret
- Vanessa Kirby as young Princess Margaret
- Dominic West as Prince Charles
- Elizabeth Debicki as Diana, Princess of Wales
- Jonny Lee Miller as John Major
- Olivia Williams as Camilla Parker Bowles
- Claudia Harrison as Princess Anne
- Natascha McElhone as Penelope Knatchbull
- Marcia Warren as Queen Elizabeth, The Queen Mother
Recurring[]
- Salim Daw as Mohamed Al-Fayed
- Amir El-Masry as young Mohamed Al-Fayed
- Khalid Abdalla as Dodi Fayed
- Alex Jennings as Edward, Duke of Windsor
- Lia Williams as Wallis, Duchess of Windsor
- Timothy Dalton as Peter Townsend
- Ben Miles as young Peter Townsend
- Prasanna Puwanarajah as Martin Bashir
- Bertie Carvel as Tony Blair
- Flora Montgomery as Norma Major
- Andrew Havill as Robert Fellowes
- James Murray as Prince Andrew
- Emma Laird Craig as Sarah, Duchess of York
- Sam Woolf as Prince Edward
- Senan West as Prince William
- Will Powell as Prince Harry
- Chayma Abdelkarimi as young Samira Khashoggi
- Humayun Saeed as Hasnat Khan
- Lydia Leonard as Cherie Blair
- Philippine Leroy-Beaulieu as Monique Ritz
- Theo Fraser Steele as Timothy Laurence
- Jude Akuwudike as Sydney Johnson