| 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 |
| Maggie Smith | Violet Crawley, Dowager Countess of Grantham |
| Ed Speleers | Jimmy Kent |
| Cara Theobold | Ivy Stuart |
| Penelope Wilton | Isobel Crawley |
| Andrew Scarborough | Tim Drewe |
| Raquel Cassidy | Baxter |
| Brendan Patricks | Evelyn Napier |
| Julian Ovenden | Charles Blake |
| Gary Carr | Jack Ross |
| Daisy Lewis | Sarah Bunting |
| Samantha Bond | Lady Rosamund Painswick |
| Tom Cullen | Anthony Gillingham |
| Nigel Harman | Green |
| Joshua Richards | Stall Holder |
| Douglas Reith | Lord Merton |
| Philip Wallace | Stage Door Keeper
(as Philip Scott-Wallace) |
| Richard Dempsey | Footman |
| Paul Copley | Mr. Mason |
| Susie Coats | Nanny Crawley |
| Gintare Beinoraviciute | Kitchen Maid
(uncredited) |
| Jefferson King | Maitre D'
(uncredited) |
| Dan Stevens | Matthew Crawley
(uncredited) |