Elizabeth Castor (née Bowe; born May 11, 1941) is an American educator and former politician. Castor was elected to the Florida Senate and as Florida Education Commissioner, and she subsequently served as the President of the University of South Florida, and President of the National Board for Professional Teaching Standards. Her public service included three terms in the Florida State Senate and one term as a Hillsborough County Commissioner. In 2004, she was the Democratic nominee for the open U.S. Senate seat of retiring Senator Bob Graham and was narrowly defeated by Mel Martinez.