Sir Geoffrey Jellicoe (8 October 1900 – 17 July 1996) was an English landscape architect, garden designer, architect and author.
Jellicoe was born in Chelsea. He studied at the Architectural Association in London in 1919 and won a Rome Scholarship in 1923 which enabled him to research his first book Italian Gardens of the Renaissance with John C. Shepherd. This pioneering study did much to re-awaken interest in this great period of landscape design and through its copious photographic illustrations publicized the then perilously decayed condition of many of the gardens.
In 1929 he was a founding member of the Landscape Institute and from 1939 to 1949 he was its President. In 1948, he became the founding President of the International Federation of Landscape Architects (IFLA). From 1954 to 1968 he was a member of Royal Fine Art Commission and from 1967 to 1974 a Trustee of Tate Gallery.
On 11 July 1936, he married Susan Pares (1907–1986), the daughter of Sir Bernard Pares KBE (1867–1949), the historian and academic known for his work on Russia.
He died in 1996, the best-known English landscape architect of his generation.