An activist for feminist issues, Merle Thornton, with a friend, chained herself to the footrail of the men-only public bar in Brisbane's Regatta Hotel in the 1960s, and following that she formed the Equal Opportunities for Women Association. She led the successful campaign to eliminate the 'marriage bar' which until 1966 excluded married women from career public service in Australia.
She introduced the teaching of Women's Studies in Australia at the University of Queensland in 1973 and was a strong fighter for Australian feminism throughout her career as an academic in philosophy, politics and sociology. She published a number of papers on feminist issues. In 2020, The University of Queensland awarded her an Honorary Doctor of Letters, and launched the Merle Pledge, an initiative to improve women's representation in public and professional forums.
Mother of actress Sigrid Thornton, she had a play produced and wrote episodes for the television drama series Prisoner. She also wrote and produced documentaries.