The defender has joined the Canaries for an undisclosed fee and has penned a four-year contract.
"Being able to come to a massive club and get games is a big motivation for me," Hanley told the club's official website.
"It’s a club with high aspirations and a fresh start for me. As a defender, I’m a bit of an old-fashioned no-nonsense centre-half and you pride yourself on clean sheets.
"We’ve got work to do on the training ground to improve that so I’m looking to hit the ground running. I can’t wait to get started."
Hanley only moved to Newcastle last summer after six years at Blackburn Rovers but struggled to make an impact under Rafa Benitez.