Perch has signed a four-year deal after Newcastle accepted an undisclosed bid and becomes Owen Coyle's fourth signing as Wigan boss.
The 27-year-old, who can play in defence or midfield, leaves Tyneside three years after he arrived from Nottingham Forest.
He told the Wigan website: "It feels great to be here with a new challenge ahead of me, and I'm very excited at getting that started.
"The prospect of helping to get the team promoted was really appealing and I can't wait to meet the rest of the boys and get started.
"I think Wigan Athletic is a great club and after speaking with the manager, his ambition and determination to take the club back to the Premier League where it belongs is something I wanted to be a part of."
Perch joins fellow new boys Chris McCann, Thomas Rogne and Stephen Crainey at the DW Stadium ahead of the Championship season.