The 51-year-old has signed a three-and-a-half-year deal at Hillsborough and replaces Brian Laws, who left the club by mutual consent in December.
Irvine was sacked as manager at Deepdale shortly before Christmas after two years in charge.
"I am delighted. It is a club with great traditions and a brilliant outlook for the future," Irvine said.
"While the league table shows us that there is a lot of hard work in front of us between now and the end of the current season, it's a challenge I'm relishing and I believe the squad here at Hillsborough is more than capable of pulling away from the current situation at the bottom of the Championship.
"Sheffield Wednesday has made excellent progress off the pitch in the past 12 months and it is now my job to make sure that progress is mirrored on the pitch.
"I'm really looking forward to starting work with the players and I can't wait to get out on the training pitch to start preparing for the vital matches we have coming up this month."

Happy Owls fans?

great appointment by Strafford yesterday, just what the club needs, a hard working no-nonsense guy who can get the most out of this lazy excuse of a squad.

can't even believe people are against this appointment - who on earth did people think we were going to get?

we need discipline, knowledge and organisation right now and we've got a manager who is going to give us that.

can't wait for Barnsley away next week now.

ALAN IRVINE'S BARMY ARMY!!!

UTO

Make no mistake, this is the best managerial appointment we've made since Francis was manager. Yorath, Pleat, Shreeves, Jewell, Wilson, particularly Turner and even Laws (though I warmed to the guy), all of these filled me with a sense of foreboding. Only Sturrock seemed like the type of manager to make an impact and of course he did.

he's good, he's very good. Brilliant news and looking forward to a successful season