The title of Earl of Llandaff was created in 1797 in the Peerage of Ireland for Francis Mathew, 1st Viscount Llandaff, who had been created Baron Llandaff in 1783 and Viscount Llandaff in 1797. These titles all became extinct upon the death of the 2nd Earl in 1833.

The title of Viscount Llandaff was created again in 1895, this time in the Peerage of the United Kingdom, for Henry Matthews, the former Home Secretary, and became extinct upon his death in 1913.

Earls of Llandaff (1797)

• Francis Mathew, 1st Earl of Llandaff (1738-1806), elected a Representative Peer in 1800
• Francis James Mathew, 2nd Earl of Llandaff (1768-1833)

Viscounts Llandaff (1895)

• Henry Matthews, 1st Viscount Llandaff (1826-1913)