The Stanley Cup champions announced the deal Monday for King, a restricted free agent.
King's signing means every player who suited up during the Kings' Stanley Cup run is under contract for next season.
King scored five playoff goals last season for Los Angeles, tied with Calder Trophy finalist Adam Henrique of New Jersey for the most post-season goals among rookies.
King was promoted to Los Angeles on Feb. 10 and immediately earned a regular lineup spot alongside fellow rookie Jordan Nolan. King scored 14 points in 27 regular-season games before Los Angeles' run to its first NHL title.
King turned 23 on July 5. The former fourth-round pick made his NHL debut in November 2010.
You can be hyped all you want, but his game will speak for itself. He's obviously going to be a great player so we've got to make sure we keep an eye on him. Whether it's his first game or his 1,000th game, our job is to take care of business, shut him down.
— Blues defenseman Alex Pietrangelo on facing ballyhooed Oilers rookie Connor McDavid, who is making NHL debut in St. Louis
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