Sir Geoffrey Holt Seymour Jackson KCMG (4 March 1915 – 1 October 1987) was a British diplomat and writer.
In 1971, during his tenure as British ambassador to Uruguay, he was kidnapped by the Tupamaros guerrillas and ultimately released after eight months of captivity.
He entered the Foreign Service in 1937 and served in Beirut, Cairo, Baghdad, Basra, Bogotá and Bern before being appointed Minister to Honduras in 1956.
Released in September 1971, he retired at the end of 1972 with the honorary rank of Deputy Under-Secretary of State at the Foreign Office, having served for 35 years in the diplomatic service, of which 31 had been spent abroad.
Three decades later it became known that Edward Heath, the UK Prime Minister at that time, negotiated a deal for Jackson's release, brokered by Salvador Allende, President of Chile, who was in contact with the Tupamaros rebels.