Louisa Petty, Marchioness of Lansdowne, known as the Countess of Shelburne from 1779–84, was an Anglo-Irish aristocrat from the Mac Giolla Phádraig dynasty. She was the wife of Prime Minister William Petty, 2nd Earl of Shelburne.
- Occupation
- aristocrat
- Position held
- spouse of the prime minister of the United Kingdom
- Citizenship
- Kingdom of Great Britain
- Born
- 1755
- Died
- 1789, August 7, 1789
