Margaret Flowers is an American pediatrician, public health advocate and activist. After 17 years of practicing medicine, she became an advocate for a single-payer insurance system. Flowers is an adviser to the board of Physicians for a National Health Program, serving as a Congressional Fellow during the health reform process in 2009-10 and is co-chair of the Maryland chapter. She was co-chair of the Green Party of the United States until 2020. In 2011, Flowers organized with the Occupy Movement in Washington, D.C., which evolved into her work at Popular Resistance in 2013, which she co-directed with Kevin Zeese.