It was Cheechoo's eighth career hat trick. In his past 10 games, he has 17 points (12 goals and five assists).
Cheechoo broke open the 1-1 game when he scored his first goal at 2:49 of the second from the top of the blue line on a power play.
His second goal gave San Jose a 3-1 lead and his third goal of the period gave the Sharks a 5-1 lead when he converted on a power play. Cheechoo, who led the NHL in goals last season with 56, has 35 this season.
The Kings have scored seven goals in their past five games with six of the seven coming on the power play. They've lost four straight games.
The win moved the Sharks back into a tie with the Dallas Stars for the fifth place in the Western Conference. San Jose and the Stars each have 102 points. Anaheim leads both teams with 106 points.
The Sharks visit the Ducks on Wednesday night.