The 26-year-old was a restricted free agent and scheduled for an arbitration hearing on July 20. With an average annual value of $4.4 million, his new contract makes him the team's highest-paid netminder.
Binnington enjoyed one of the best rookie campaigns from a goalie in NHL history during the 2018-19 season. The Ontario native joined the struggling Blues on Dec. 16 and posted a 24-5-1 regular-season record with a 1.89 goals against average and a .927 save percentage, lifting the club from last place in the NHL to the third seed in the Central Division.
In the playoffs, Binnington went 16-10 with a 2.46 goals against average and a .914 save percentage, guiding the Blues to the first championship in franchise history. He also became the first rookie goalie to register 16 wins in a single postseason.
"I'm happy to get this deal done with the St. Louis Blues," Binnington said. "To the city of St. Louis, thank you for welcoming me in and trusting me to do me. I'm excited and motivated to keep doing my job and keep bringing success to the St. Louis Blues organization."
Binnington was nominated for the 2019 Calder Memorial Trophy and named to the NHL All-Rookie Team.
The Blues hold $7.12 million in projected cap space, with restricted free-agent forwards Ivan Barbashev and Oskar Sundqvist and defenseman Joel Edmundson in need of new deals, according to CapFriendly.
St. Louis selected Binnington with the 88th pick in the 2011 NHL Draft.