Mary Jane Rathbun (December 22, 1922 – April 10, 1999), popularly known as Brownie Mary, was an American medical cannabis rights activist. As a hospital volunteer at San Francisco General Hospital, she became known for baking and distributing cannabis brownies to AIDS patients. Along with activist Dennis Peron, Rathbun lobbied for the legalization of cannabis for medical use, and she helped pass San Francisco Proposition P (1991) and California Proposition 215 (1996) to achieve those goals. She also contributed to the establishment of the San Francisco Cannabis Buyers Club, the first medical cannabis dispensary in the United States.