The titles of Marquess Grey and Earl de Grey were created in the peerages of Great Britain and the United Kingdom respectively for descendants of the Greys, Earls of Kent, who were unrelated to the family of the Earls Grey.

Henry Grey, 12th Earl, 1st Marquess and 1st Duke of Kent was created Marquess Grey in 1740. As this title had a special remainder, it did not become extinct on his death later that year, along with his other titles, but passed to his grand-daughter Jemima (née Campbell), Countess of Hardwicke, who was the daughter of Lady Amabel Grey by her husband the 3rd Earl of Breadalbane. The title became extinct on her death in 1797.

The 2nd Marchioness de Grey's daughter Amabel, suo jure Baroness Lucas, was created Countess de Grey in 1816. On her death without issue, the title passed to her sister's son Thomas, 3rd Baron Grantham, who became 2nd Earl de Grey and adopted the name of "de Grey". He died in 1859, when the Earldom passed to his nephew George, 2nd Earl of Ripon (son of the Prime Minister Lord Goderich). The 2nd Earl of Ripon and 3rd Earl de Grey was created Marquess of Ripon in 1871, and was succeeded in 1909 by his son Frederick, who became 4th Earl de Grey, 3rd Earl of Ripon, 2nd Marquess of Ripon, 3rd Viscount Goderich, and 5th Baron Grantham. All the titles became extinct on his death in 1923.

Marquess Grey (1740)

• Henry Grey, 1st Marquess Grey, 1st Duke of Kent (1671-1740)
• Jemima Yorke, 2nd Marchioness Grey (1722-1797)

Earl de Grey (1816)

• Amabel Yorke, 1st Countess de Grey, 5th Baroness Lucas (1751-1833)
• Thomas Philip de Grey, 2nd Earl de Grey, 3rd Baron Grantham (1781-1859)
• George Frederick Samuel Robinson, 3rd Earl de Grey, 1st Marquess of Ripon (1827-1909)
• Frederick Oliver Robinson, 4th Earl de Grey, 2nd Marquess of Ripon (1852-1923)