John A. Hart., Jr., known as Jack Hart (born April 21, 1961), is an American lawyer and former state legislator who served as a Democratic member of the Massachusetts Senate from 2002 to 2013. He was educated at Boston College High School, Worcester Academy, Tufts University (B.A.), and Harvard Kennedy School at Harvard University (M.P.A.). Hart also graduated from New England Law - Boston (J.D.).