"I am really pleased to be able to continue my development as a young player with Norwich, where the manager has given me this chance to come in and fight for a place in the team," said the former Royal Antwerp trainee.
"I know it's going to be very tough because the lads there have done really, really well and it's going to be a big challenge to get into a team which is really used to winning and is a great, tight-knit group."
De Laet added: "I am sure everybody can't wait to get going. Every game will be very tough and competitive, that's what the Premier League is all about.
"I am looking forward to joining in with pre-season training and getting to know the rest of the lads as we all start getting down to some serious work and then the friendlies before the Premier League starts."