The 22-year-old will get an annual average value of $6 million, according to reports.
"It's really rewarding, but I'm mostly really excited for the future," Meier said, according to the Sharks. "I want to take my game up to the next level next season, want to keep improving."
Meier reached the 30-goal plateau this past season, adding 36 assists to nearly double his point total from his 36 the year before.
In the playoffs, Meier also took it to another level with five goals and 10 assists in 20 games.
"Timo is one of only a few young, dominant power forwards in the NHL and we're extremely pleased that he stepped forward to make this commitment to the Sharks," Sharks general manager Doug Wilson said in a statement. "Timo has elevated himself into a core part of our hockey team and his play last season was a huge part of our success. We feel that his best hockey is still ahead of him."
Meier was the ninth overall pick in the 2015 draft and just completed a three-year entry-level contract with a cap hit of $894,167.