Accents of characters in Downton Abbey

Solution 1:

• Charles Carson - butler: Yorkshire (ref)
• John Bates - the earl's valet
• Sarah O'Brien - the countess's maid
• Anna Smith - Lady Mary's maid
• Thomas Barrow - footman: Mancunian (ref)
• Mrs. Hughes - housekeeper: West Scots (ref 1, ref 2)
• Daisy Mason - cook's aid
• Mrs. Patmore - cook: Mancunian (ref)
• Tom Branson - chauffeur
• Joseph Molesley - footman
• Dr. Clarkson - physician
• Ethel Parks - maid
• William Mason - footman: Yorkshire (ref)

Solution 2:

Miss O'Brien regularly speaks in a gently scouse accent from the Liverpool area, West Midlands. This would also be consistent with her Irish surname.