The title Marquess of Dorset has been created three times in the Peerage of England. It was first created in 1397 for John Beaufort, 1st Earl of Somerset, but he lost the title two years later. It was then created in 1442 for Edmund Beaufort, 1st Earl of Dorset, who was created Duke of Somerset in 1448. That creation was attainted in 1463.
It was created a third time in 1475 for Thomas Grey, 1st Earl of Huntingdon, who then resigned the earldom. The Marquess held the subsidiary title of Baron Ferrers of Groby (1300). The third marquess was created Duke of Suffolk in 1551, but he was attainted in 1554 and all the peerages were forfeited.