| Earl of Merioneth | |
| Creation Date: | 20 November 1947 |
| Creation: | First |
| First Holder: | Philip, Duke of Edinburgh |
| Last Holder: | Charles, Prince of Wales |
| Remainder To: | the 1st Earl's heirs male of the body lawfully begotten |
| Status: | Merged with crown |
| Extinction Date: | 8 September 2022 |
| Former Seat: | Clarence House |
Earl of Merioneth was a title in the Peerage of the United Kingdom created in 1947 along with the Duke of Edinburgh and the Baron Greenwich for Philip Mountbatten, later Prince Philip, upon his marriage to Princess Elizabeth, later Queen Elizabeth II.
Merionethshire is one of thirteen historic counties of Wales, a vice county and a former administrative county.
| Prince Philip
Mountbatten
1947–2021
also: Duke of Edinburgh and Baron Greenwich (1947)| | 10 June 1921
Mon Repos, Corfu
son of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg| Princess Elizabeth
20 November 1947
4 children| 9 April 2021
Windsor Castle, Windsor
aged 99|-| Prince Charles[1]
House of Windsor
2021–2022
also: Prince of Wales and Earl of Chester (1958), Duke of Cornwall, Duke of Rothesay (1952), Duke of Edinburgh and Baron Greenwich (2021)| | 14 November 1948
Buckingham Palace, London
son of Prince Philip and Queen Elizabeth II| Lady Diana Spencer
29 July 198128 August 1996
2 children
Camilla Parker Bowles
9 April 2005|
now old|-| colspan=5|Prince Charles succeeded as Charles III in 2022 upon his mother's death, and his hereditary titles merged in the Crown.|}