Justin Paul Leone (born March 9, 1977) is an American former professional baseball third baseman. He is an alumnus of St. Martin's University. Drafted by the Seattle Mariners in the 13th round of the 1999 Major League Baseball Draft, Leone made his Major League Baseball debut with the Seattle Mariners on July 2, 2004. He spent the 2006 season in the San Diego Padres organization, making the Triple-A All-Star team that year, in which he also participated in the home run derby. He was a part of the 2003 USA Olympic Qualifying Team.