"From my perspective, it's pretty incredible that they gave me such a vote of confidence to trust me for the next nine years, including this one," Matheson said. "I'm excited about where this team is headed and it's such an honor to be a part of it for such a long time."
Matheson is plus-2 with four shots on goal in two games this season. He had 17 points (seven goals, 10 assists) in 81 games last season. He was selected by the Panthers with the No. 23 pick of the 2012 NHL Draft.
"It's a great deal for both sides and he's going to be here for long time," Panthers coach Bob Boughner said.
In addition to his NHL success, Matheson helped Canada win a silver medal at the 2017 IIHF World Championship with seven points (one goals, six assists) in 10 games. At the 2016 Worlds, he had six points (two goals, four assists) in 10 games, helped Canada win the gold medal and was named the tournament's best defenseman.
"Mike is an important part of our team's young core and we are thrilled that he has decided to remain a Panther for the long term," Panthers general manger Dale Tallon said. "He is a dynamic and intelligent defenseman with impeccable character and work ethic. Mike has developed into a difference maker on our blue line and will be an important player and leader for the Panthers for many years to come."