General manager Ron Francis on Wednesday said the deal begins in 2018-19 and will carry an average annual value of $5.3 million through the 2024-25 season.
Francis says the 23-year-old Slavin is "one of the cornerstones of our team" and "one of the top young defensemen in the NHL today."
In his second season in the NHL in 2016-17, Slavin had 34 points, five goals, 29 assists. He also led the team with 161 blocked shots, 83 takeaways and an average time on ice of about 23-plus minutes.
Slavin, Brett Pesce and Noah Hanifin are the team's key defensemen entering their third NHL season, and they along with All-Star Justin Faulk and trade acquisition Trevor van Riemsdyk will enter the season as the nucleus of the defense in front of new goalie Scott Darling.
The Hurricanes have not had a captain since Eric Staal was traded in 2016, going with a group of alternate captains last season. Slavin understands that his lengthy new contract comes with an expectation that he will help lead a young dressing room, whether or not he earns an "A" or a "C" on his jersey.
"Letter or no letter, it doesn't matter -- I'm going to be who I am," Slavin said. "I don't think that's going to change the way I play or change the way I am in the locker room. ... I want to contribute as a leader and be a leader on this team for a long time, letter or no letter."
His entry-level contract expires after this season, and he would have been eligible for restricted free agency in July 2018.