| Hugh Bonneville | Robert Crawley, Earl of Grantham |
| Laura Carmichael | Lady Edith Crawley |
| Jim Carter | Charles Carson |
| Brendan Coyle | John Bates |
| Michelle Dockery | Lady Mary Crawley |
| Kevin Doyle | Joseph Molesley |
| Joanne Froggatt | Anna Bates |
| Lily James | Lady Rose MacClare |
| Robert James-Collier | Thomas Barrow
(as Rob James-Collier) |
| Allen Leech | Tom Branson |
| Phyllis Logan | Mrs. Hughes |
| Elizabeth McGovern | Cora Crawley, Countess of Grantham |
| Sophie McShera | Daisy Mason |
| Matt Milne | Alfred Nugent |
| Lesley Nicol | Mrs. Patmore |
| David Robb | Dr. Clarkson |
| Maggie Smith | Violet Crawley, Dowager Countess of Grantham |
| Ed Speleers | Jimmy Kent |
| Cara Theobold | Ivy Stuart |
| Penelope Wilton | Isobel Crawley |
| Tom Cullen | Anthony Gillingham |
| Nigel Harman | Green |
| Andrew Alexander | Sir John Bullock |
| Charles Edwards | Michael Gregson |
| Joanna David | Duchess of Yeovil |
| MyAnna Buring | Edna Braithwaite |
| Patrick Kennedy | Terence Sampson |
| Kiri Te Kanawa | Dame Nellie Melba |
| Gintare Beinoraviciute | Kitchen Maid
(uncredited) |
| Dan Stevens | Matthew Crawley
(uncredited) |