John Joseph Rizzo (born October 3, 1980) is an American politician serving as a Democratic member of the Missouri Senate since January 2017. In 2020, Rizzo was elected by his colleagues to serve as Minority Floor Leader. Prior to his election into the Senate, Rizzo was a member of the Missouri House of Representatives, serving the 19th and 40th districts from 2011 to 2017. In the House, Rizzo also served as Democratic Minority Whip.