Conn was a four-year starter at Holy Cross Catholic Secondary School in St. Catharines from 1997 to 2001. During those years, he teamed up with fellow future NLL players Matt Vinc, Billy Dee Smith and Sean Greenhalgh to win two OFSAA field lacrosse championships. After Conn graduated, many St. Catharines lacrosse players would follow in Conn's footsteps and play for Holy Cross, which would help the school become a lacrosse powerhouse for years.
Conn was originally drafted by the Vancouver Ravens in the first round of the 2003 NLL Entry Draft. In the 2004 season, he was 4th in team scoring with 39 points and was named to 2004 NLL All-Rookie Team. When the Ravens were removed from the 2005 schedule, a dispersal draft was held, and Conn was taken 1st overall by the Minnesota Swarm. After only playing half a season with Minnesota, Conn was dealt at the trade deadline to the Arizona Sting for their first round draft picks in 2006 & 2007. Conn led Arizona in scoring with 19 points during their playoff run to the 2005 Championship game. Conn also helped lead Arizona to the 2007 Championship game, before losing to the Rochester Knighthawks. Prior to the 2008 season, the Sting announced that they would not play in 2008, and another dispersal draft was held. Conn was selected by the Buffalo Bandits despite suffering a major knee injury during the summer that sidelined him for the entire 2008 season. The Sting would have retained Conn's rights if they returned in the 2009 season. However, the Sting ceased operations and another dispersal draft was held. Conn, never having played a game in a Bandits uniform, was selected fourth overall by the Toronto Rock. After one season with the Rock, Conn was traded along with a second round draft pick to the Calgary Roughnecks in exchange for two draft picks. Conn played for the Washington Stealth during the 2011 season and retired after the season.
In the WLA draft, Conn was selected 2nd overall by the New Westminster Salmonbellies. During the 2007 season, Conn sufferered a major knee injury while playing with the Salmonbellies during the Western Lacrosse Association's playoffs. This would cause Conn to miss the entire 2008 NLL season as well as the 2008 WLA season. Conn made his return to Senior lacrosse in 2009 with the Six Nations Chiefs of Major Series Lacrosse. Conn returned to the Salmonbellies for the 2010 season where he played in the Mann Cup, losing to the Peterborough Lakers. Conn retired from Senior lacrosse after the season.
