A prolific radio dramatist Catherine Duncan produced plays in Australia, New Zealand, UK and France. She was director and writer for the Melbourne Writers' Group during the late 1930s and also wrote and directed numerous documentary films. In 1947 she left Australia for France, where she continued to write and work on collage.
In 1986 Duncan visited Australia for the premier of her audio-visual spectacle Shadow of Light at the Victorian Arts Centre, Melbourne.
Duncan is the mother of Michael Keane.