The Duke of Portland is a peerage title created in 1716 for Henry Bentinck , who was already Earl of Portland. The dukedom came into the possession of the Cavendish-Bentinck family by marriage. The Dukedom of Portland became extinct on the 9th Duke's death, though the 9th Duke's distant cousin succeeded him as Earl of Portland.

Dukes of Portland (1716)

• Henry Bentinck, 1st Duke of Portland (1682-1726)
• William Bentinck, 2nd Duke of Portand (1708-1762)
• William Henry Cavendish-Bentinck, 3rd Duke of Portland (1738-1809)
• William Henry Cavendish-Scott-Bentinck, 4th Duke of Portland (1768-1854)
• William John Cavendish Bentinck-Scott, 5th Duke of Portland (1800-1879)
• William John Arthur Charles James Cavendish-Bentinck, 6th Duke of Portland (1857-1943)
• William Arthur Henry Cavendish-Bentinck, 7th Duke of Portland (1893-1977)
• Ferdinand William Cavendish-Bentinck, 8th Duke of Portland (1888-1980)
• Victor Frederick William Cavendish-Bentinck, 9th Duke of Portland (1897-1990)