The team did not release the terms of the deal but according to the Los Angeles Times, Johnson signed a lucrative three-year, entry-level contract. The maximum he can make in base salary is US$850,000 per year, but with bonuses, he could earn as much as $2 million per season, a source told the Times.
He's expected to join the Kings for practice Wednesday.
Johnson, 20, was selected third overall by the Carolina Hurricanes in the 2005 NHL draft behind Penguins star Sidney Crosby and Anaheim prospect Bobby Ryan. The six-foot-one, 215-pound native of Indianapolis was acquired by the Kings along with defenceman Oleg Tverdovsky in exchange for centre Eric Belanger and defenceman Tim Gleason in September.
Johnson recently completed his sophomore season at the University of Michigan. He helped lead the Wolverines to the NCAA West Hockey Regional semifinals this season, recording 16 goals and 23 assists with 87 penalty minutes in 36 games.
He also played for the U.S., at the 2006 and 2007 world junior hockey championships.