William Wellesley-Pole, 3rd Earl of Mornington, was born 20 May 1763 in Dangan Castle, County Meath, Ireland to Garret Colley Wesley, 1st Earl of Mornington (1735-1781) and Anne Hill-Trevor (1742-1831) and died 22 February 1845 Grosvenor Square, Mayfair, London, England, United Kingdom of unspecified causes. He married Katherine Elizabeth Forbes (1761-1851) 17 May 1784 in Saville Row, Mayfair, London, England, United Kingdom.
|Offspring of William Wellesley-Pole, 3rd Earl of Mornington and Katherine Elizabeth Forbes (1761-1851)|
|Mary Charlotte Anne Wellesley-Pole (1786-1845)|
|William Pole-Tylney-Long-Wellesley, 4th Earl of Mornington (1788-1857)|
|Emily Harriet Wellesley-Pole (1792-1881)|
|Priscilla Anne Wellesley-Pole (1793-1879)||13 March 1793||18 February 1879 29 Portman Square, London, England, United Kingdom||John Fane, 11th Earl of Westmorland (1784-1859)|