Corry has put pen to paper on a three-year contract at Hillsborough and goes straight into manager Dave Jones' first-team squad.
"I have bided my time for the right move at the right time and this is it for me," said Corry. "Sheffield Wednesday is a club with a huge heritage and history and the stadium just blows you away.
"I really can't wait to get started and, like everyone else at the club, I have ambitions of playing in the Premier League. But it's one step at a time, I know it will be difficult at first but once I settle in and get my sharpness, I have the confidence in my ability to do well for Sheffield Wednesday."
Corry is widely regarded as an outstanding young talent in his homeland. The 21-year-old played almost 100 games for UCD, scoring 14 goals from central midfield, before earning a recent call-up to the Republic of Ireland Under-21 squad for their Euro 2013 qualifier against Turkey.
At just 18-years-old, Corry was offered a contract by then-Premier League newcomers Burnley but opted to stay in Ireland to further both his football development and education.