Earl of Bessborough is a peerage title in the Peerage of Ireland. Other titles held by the Earl include: Viscount Duncannon (created 1723, Peerage of Ireland), Baron Bessborough (1721, Peerage of Ireland), Baron Ponsonby of Sysonby (1749, Peerage of Great Britain) and Baron Duncannon (1834, Peerage of the United Kingdom).

Viscounts Duncannon (1723)

• William Ponsonby, 1st Viscount Duncannon (1659-1724)
• Brabazon Ponsonby, 2nd Viscount Duncannon (1679-1758) (became Earl of Bessborough in 1739)

Earls of Bessborough (1739)

• Brabazon Ponsonby, 1st Earl of Bessborough (1679-1758)
• William Ponsonby, 2nd Earl of Bessborough (d. 1793)
• Frederick Ponsonby, 3rd Earl of Bessborough (1758-1844)
• John William Ponsonby, 4th Earl of Bessborough (1781-1847)
• John George Brabazon Ponsonby, 5th Earl of Bessborough (1809-1880)
• Frederick George Brabazon Ponsonby, 6th Earl of Bessborough (1815-1895)
• Walter William Brabazon Ponsonby, 7th Earl of Bessborough (1821-1906)
• Edward Ponsonby, 8th Earl of Bessborough (1851-1920)
• Vere Brabazon Ponsonby, 9th Earl of Bessborough (1880-1956)
• Frederick Edward Neuflize Ponsonby, 10th Earl of Bessborough (1913-1993)
• Arthur Mountifort Longfield Ponsonby, 11th Earl of Bessborough (1912-2002)
• Myles Fitzhugh Longfield Ponsonby, 12th Earl of Bessborough (b. 1941)