Gunn, the son of former Canaries keeper Bryan, will return to East Anglia on July 1 having spent a number of years with the club’s academy prior to his 2011 move to Manchester.
“I grew up as Norwich fan and ever since I was a little boy I came to Carrow Road for every home game,” the 21-year-old told the Sky Bet Championship side’s website.
“It’s a great pleasure for me to come back and sign on loan. The main thing for me is to come and get experience, so to mix that in with coming to Norwich is a great feeling.”
Gunn is currently representing his country at the Under-21 European Championships in Poland.
City sporting director Stuart Webber said: “He’s an unbelievably talented goalkeeper.
“It’s a name dear to the supporters’ hearts but we’re judging Angus on being Angus. We’re really excited to have him here.”