Nancy Keesing was born in Sydney and educated at Sydney Girls' Grammar School and the University of Sydney. Garden Island People (1975), a memoir, describes her war-time work with the Senior Service at Garden Island and she was a social worker at the Royal Alexandra Hospital for Children (1947-51). Her long association with Sydney is reflected in much of her work. A versatile writer, she was active in various literary associations; for example, the Australian Society of Authors, whose journal TheAustralian Author, she edited from 1971 to 1974.
Riding the Elephant (1988), her autobiography, describes in vivid detail her association with many well-known literary people and organisations in Australia, starting with her work in the Bulletin offices in 1952. Douglas Stewart (q.v.) was an early mentor and Kylie Tennant (q.v.) was a neighbour in Hunters Hill for twenty years. Keesing's own work covered several genres, including editorial and critical roles, poetry, children's novels and biography.