Earl of Radnor is a title which has been created several times, first in the Peerage of England in 1679 for Lord Robartes, a notable political figure of the reign of Charles II, and then in the Peerage of Great Britain in 1765.

The current Earl of Radnor holds the subsidiary titles of Viscount Folkestone (1747), Baron Longford (1747), and Baron Pleydell-Bouverie (1765), all in the Peerage of Great Britain, and is a baronet of Great Britain (1714).

The family seat is Longford Castle in Wiltshire.

Earls of Radnor, First Creation (1679)

• John Robartes, 1st Earl of Radnor (1606-1685)
• Charles Bodvile Robartes, 2nd Earl of Radnor (1660-1723)
• Henry Robartes, 3rd Earl of Radnor (1695-1741)

Viscounts Folkestone (1747)

• Jacob Bouverie, 1st Viscount Folkestone (1694-1761)
• William Bouverie, 2nd Viscount Folkestone (1725-1776) (became Earl of Radnor in 1765)

Earls of Radnor, Second Creation (1765)

• William Bouverie, 1st Earl of Radnor (1725-1776)
• Jacob Pleydell-Bouverie, 2nd Earl of Radnor (1750-1828)
• William Pleydell-Bouverie, 3rd Earl of Radnor (1779-1869)
• Jacob Pleydell-Bouverie, 4th Earl of Radnor (1815-1889)
• William Pleydell-Bouverie, 5th Earl of Radnor (1841-1900)
• Jacob Pleydell-Bouverie, 6th Earl of Radnor (1868-1930)
• William Pleydell-Bouverie, 7th Earl of Radnor (1895-1968)
• Jacob Pleydell-Bouverie, 8th Earl of Radnor (b. 1927)