John DeStefano Jr. is an American politician who served as the 49th mayor of New Haven, Connecticut, from 1994 until 2014. He was the Democratic nominee in 2006 for Governor of Connecticut, unsuccessfully challenging incumbent Republican Governor M. Jodi Rell. He was also the named defendant in the landmark 2009 U.S. Supreme Court case of Ricci v. DeStefano. John DeStefano is the son of a New Haven police officer. John and his wife Kathy DeStefano met at the University of Connecticut as undergraduates, where he also earned a Masters in Public Administration. Kathy DeStefano is a first grade teacher in West Haven, Connecticut, and they are the parents of two adult sons.

The 2006 Connecticut gubernatorial election occurred on November 7, 2006. Incumbent Republican Jodi Rell became governor when John G. Rowland resigned on corruption charges in 2004. Rell had an approval rating of 70% as of October 19, 2006, and polls showed her leading the Democratic nominee, New Haven mayor John DeStefano by a near 30-point margin. As expected, she won the election to a full term in a landslide. DeStefano defeated Stamford Mayor Dannel Malloy in the Connecticut Democratic gubernatorial primary on August 8. As of 2024, this is the last time a Republican and woman was elected Governor of Connecticut, and the last time any gubernatorial candidate won every county in the state to date.