The title of Earl of Harrington was created in the Peerage of Great Britain in 1742 for the former Secretary of State and then Lord President, William Stanhope, 1st Baron Harrington.
Lord Harrington holds the subsidiary titles of Viscount Stanhope of Mahon (1717), Viscount Petersham (1742), Baron Stanhope of Elvaston, of Elvaston in the County of Derby (1717), and Baron Harrington, of Harrington in the County of Northampton (1730), all in the Peerage of Great Britain. The Viscountcy of Stanhope of Mahon and the Barony of Stanhope of Elvaston were inherited by the 11th Earl on the death of his kinsman, the 13th Earl of Chesterfield and 7th Earl Stanhope.
Earls of Harrington (1742)
- William Stanhope, 1st Earl of Harrington (1683-1756)
- William Stanhope, 2nd Earl of Harrington (1719-1779)
- Charles Stanhope, 3rd Earl of Harrington (1753-1829)
- Charles Stanhope, 4th Earl of Harrington (1780-1851)
- Leicester FitzGerald Charles Stanhope, 5th Earl of Harrington (1784-1862)
- Seymour Sydney Hyde Stanhope, 6th Earl of Harrington (1845-1866)
- Charles Wyndham Stanhope, 7th Earl of Harrington (1809-1881)
- Charles Augustus Stanhope, 8th Earl of Harrington (1844-1917)
- Dudley Henry Eden Stanhope, 9th Earl of Harrington (1859-1928)
- Charles Joseph Leicester Stanhope, 10th Earl of Harrington (1887-1929)
- William Henry Leicester Stanhope, 11th Earl of Harrington (b. 1922)
Heir Apparent:Charles Henry Leicester Stanhope, Viscount Petersham (b. 1945)
