The 20-year-old Republic of Ireland youth international scored twice against Wigan in the reserves recently and big things are expected of him in the future.
Because Corr has signed after transfer deadline day, he will not be allowed to play in the Wednesday first team but he has signed a two-year deal at Hillsborough.
Paul Sturrock told Wednesday's official website: "Barry has fantastic potential - he is 6ft 3in, has a great touch and is an exciting talent to be developed.
"I would not write off more signings between now and the end of the season. If people come who I feel could play in both the championship and league one, I would take them"
Corr was suffering from a knee problem but The Owls boss has assured supporters that the club's medical staff have checked out his previous fitness and everything seems to be fine.