The Wales international came through the academy at the east Midlands club in 2006 and has gone on to make 283 first-team appearances, scoring 54 goals.
King's previous deal was due to expire at the end of next season, but Leicester on Wednesday announced that he has been rewarded with a contract extension.
And King has spoken of his desire to end his playing days with Leicester.
He told the club's official website: "I'm absolutely buzzing. To have come so far with the club and to be playing in the Premier League now is a dream come true.
"To be able to commit my future and for the club to have shown this sort of faith in me is a massive boost so I'm just looking to kick on now.
"I've only ever played for Leicester City and it's looking more and more like they're the only team I'll ever play for. I would love it if that is the case.
"I've always said from when I made my debut against Wolves in 2007 that the fans have been nothing but brilliant with me, so I'd just like to say a big thank you to them.
"They've supported me throughout my whole career with Leicester so far and I hope that they continue to do so."
King has made six Premier League appearances for Nigel Pearson's side on their return to the top flight, starting four of those games.
