The Belgian right-back, who joined Leicester from Manchester United, has put pen to paper on fresh terms that will keep him at the King Power Stadium until 2018.
De Laet, 25, has been a mainstay at the back for the Midlands club and was a key part of the side that won the Championship title last season, guiding Leicester to promotion to the Premier League following a 10-year absence.
The former Antwerp man has played in all 11 of Leicester's Premier League games so far this season and, after securing his future, is keen to help Nigel Pearson's men retain their place in the top flight.
"I'm so happy to sign a new deal here at Leicester," De Laet told Leicester's official website.
"I'm settled, my family has settled and hopefully it'll be a good thing for the club and me. I just want to finish this year well, stay in the Premier League and kick on from there.
"Leicester took a risk with me at the start when they brought me here without a lot of experience and they stuck with me, so now I'm doing the same thing with them.
"It's been nearly the same group since I've been here. Most have signed new contracts to stay with Leicester, so we're a group that are tied together and we'll fight together to stay in the Premier League."
