Wolves boss Kenny Jacobs revealed over the weekend that an undisclosed fee had been agreed and the formalities on the transfer have now been completed.
Latics manager Gary Caldwell told the club’s official website: “I’m really pleased we’ve got this one over the line.
“Michael knows this league well, and knows what it takes to be successful at this level having played at Wolves when they were promoted in 2014.
“He is a potential match winner on his day and will add terrific competition to the squad, which is now starting to take shape.”
Jacobs leaves Molineux after two seasons and having spent time in loan at Blackpool last season.
Jackett added: “He didn’t get the game time last year that he perhaps wanted.
“We wish him all the best and I’m sure that move to Wigan is the right one.
“It’s the right one for us financially and also for him to drop down to League One and build up again by guaranteeing first team football.”