Joan Phipson was born in Warawee, New South Wales. She had no siblings and lived a childhood of travel between Australia, England and India. She was educated at Frensham School, returning later to establish there the Frensham Press. During the late 1930s she worked as a secretary in London and a copy and script writer for a radio station in Sydney. She was a telegraphist in the Woman's Auxiliary Air Force during World War II and married farmer Colin Hardinge Fitzhardinge in 1944. In the 1960s they moved to a property called Wongalong, near Mandurama, which was to remain their home for the next 40 years.
In the early 1950s Angus & Robertson published one of Phipson's stories, beginning a career that went on to produce more than two dozen books. In 1953 Good Luck to the Rider won the Book of the Year Award of the Children's Book Council of Australia. She repeated her early success when The Family Conspiracy won the same award in 1963. Her early books provided simple adventure stories. But in her later work during the 1970s and 1980s, Phipson wrote complex stories that explored themes such as fear, environmental destruction, and notions of masculinity. Her contribution to the development of Australian children's literature was recognised in 1987 with the award of the Dromkeen Medal from the Courtney Oldmeadow Children's Literature Foundation.