Sean Rooney was born on November 13, 1982 in Wheaton, Illinois where he also grew up. After graduating from Pepperdine University in 2005, Sean pursued beach volleyball on the United States’ domestic tour. But after two seasons, the outside hitter (206cm, 100kg) was ready to return to the hard court and was rewarded in 2008 as he played on the team that won the Olympic gold medal in Beijing and the FIVB World League title in Rio de Janeiro, Brazil.
Rooney was named the United States’ Men’s Player of the Year following the 2009 season in which he finished as the team's leading scorer with 258 points on 224 kills, 22 blocks and 12 aces. Rooney finished the 2010 season as the team's second-leading scorer with 198 points (3.25 points per set) on 170 kills (0.27 hitting percentage), 25 blocks (0.41 blocks per set) and three aces (0.05 aces per set) in 61 sets played. He was second on the team in kills. He also had 60 digs (0.98 digs per set), which was fourth best on the team.
Rooney has played in Russia and Korea. During the winter of 2010-11, he played for Acqua Paradiso Monza Brianza in Italy’s Serie A league.