Jill Ellen Stein (born May 14, 1950) is an American physician specializing in Internal Medicine. She was the nominee of the Green Party for President of the United States in the 2012 election. Stein was a candidate for Governor of Massachusetts in the 2002 and the 2010 elections for Massachusetts. She announced that she will once again run for the Green Party nomination for President in the 2016 U.S. presidential elections.