Mem Fox was born in Melbourne, but her father, grandfather, great- and great-great-grandfather were South Australian. Her parents sailed for Africa when she was seven months old, to serve as teachers with the London Missionary Society in Southern Rhodesia (Zimbabwe).
After attending schools in Bulawayo she spent three years at the Rose Bruford College of Speech and Drama in London, 1965-1968, where she met her future husband, Malcolm Fox. They married in 1969, and in 1970 came to Australia to live. Their daughter, Chloe, was born in 1971. Mem taught at Cabra Dominican College, and later completed a degree in Arts at Flinders University (1977) and in Education (SA CAE, Sturt, 1978 ) and a Diploma in Language Arts (1981). She began teaching at Sturt CAE in 1973, and was made Associate Professor and Senior Lecturer in the School of Education, Flinders University, in 1995. She retired from teaching in 1997.
She wrote the embryonic Possum Magic (as "Hugh, The Invisible Mouse") while she was a mature-age student at the university. The story was rejected by publishers nine times over five years but finally, reduced from three and a half pages of single-spaced typing to one and a half pages, double-spaced, it became the best-selling children's book in Australia's history, with sales of over a million. She helped set up the SA Storytellers' Guild in 1982, and performed on two storytelling series on ABC TV. Several of her readings of her own stories have been recorded on audiotape.
As well as the awards listed below, Fox has won the Advance Australia Award (1990), and Children's Magazine Award (1993). She was made a Member of the Order of Australia in 1993, awarded Flinders University Chancellor's Medal in commemoration of the Centenary of Women's Suffrage in 1994, and presented with an Honorary Doctorate of Letters from Wollongong University in 1996. Many of her children's books have been published in the USA, and several have been translated into other languages. As well as writing for children she has also written her autobiography (Mem's the Word) and books and articles on teaching and writing.