George John Charles Mercer Nairne Petty-Fitzmaurice, 8th Marquess of Lansdowne DL (27 November 1912 – 25 August 1999) was a British peer and Conservative politician. He held the office of Justice of the Peace for Perthshire in 1950. He held the office of Deputy Lieutenant of Wiltshire in 1952. He held the office of Lord-in-Waiting between 1957 and 1958. He held the office of Joint Parliamentary Under-Secretary of State, Foreign Office between 1958 and 1962. He held the office of Minister of State, Commonwealth and Colonial Affairs between 1962 and 1964. He was invested as a Privy Counsellor in 1964.
Petty-Fitzmaurice was the son of Lord Charles Petty-Fitzmaurice and grandson of Henry Petty-FitzMaurice, 5th Marquess of Lansdowne. His cousins, the 7th Marquess of Lansdowne and the 7th Marquess's younger brother, were both killed in action in August 1944 and Petty-FitzMaurice thus unexpectedly inherited his titles, except for the Lordship of Nairne, which was inherited by the 7th Marquess's sister Katherine Evelyn Constance Bigham (1912–1995). After his father's death, Petty-Fitzmaurice's mother Violet became the wife of John Jacob Astor, 1st Baron Astor of Hever.
Petty-Fitzmaurice married four times, his wives being: