Stevens is the first NHL coach to lose his job this season.
The Kings are tied with the Florida Panthers for the fewest points in the league with nine. Despite signing Ilya Kovalchuk in the offseason to boost the offense, Los Angeles is last in the league in goals with 28. The Kings haven't been completely healthy, however, with starting goalie Jonathan Quick out indefinitely after knee surgery.
"This is a critical time in our season and our results to date have fallen well below our expectations," general manager Rob Blake said in a statement. "With that in mind, this was a difficult decision but one we feel was necessary.
"We have a great deal of respect and appreciation for John's time with our organization. He was a key part of our past success, and we have tremendous gratitude for his many contributions."
Stevens, 52, had been an assistant with the Kings since 2010 before being named head coach in April 2017 to replace Darryl Sutter. Stevens led Los Angeles to 98 points and a playoff berth last season, but they were swept by the Golden Knights in the first round.
The Kings have the second-oldest roster in the league, behind only Minnesota.
Assistant coach Don Nachbaur was also fired. Nachbaur will be replaced by former NHL player Marco Sturm, who is the current coach and general manager of the German national team.
Desjardins, 61, coached the Canucks from 2014 to '17, and was an associate head coach with the Dallas Stars from 2010 to '12.