Huberdeau was the team’s leader in points last season with 15 goals and 39 assists last season. Huberdeau, 22, won the Calder Trophy in 2012-13 as the league's top rookie.
The two sides had discussed signing Huberdeau, a restricted free agent, to a one-year offer sheet, but that would have made him an unrestricted free agent next offseason.
The deal will pay Huberdeau $2.5 million in the first year and $4 million in the second.
The Panthers finished with 91 points last season, narrowly missing the postseason. Florida has made the playoffs just once in the last 14 seasons.