Smith got a five-year, $25 million extension that will keep him under contract through the 2021-22 season. His deal was announced not long after Trocheck finalized his six-year, $28.5 million contract with the club.
"Reilly was a key player for our team last season," general manager Tom Rowe said. "He is a valuable contributor to our offense and special teams and is an important part of our talented group of forwards."
Smith and Trocheck combined for 50 goals -- 25 each -- and 53 assists last season. Trocheck had 28 assists while Smith had 25 for the Atlantic Division winners, who made the playoffs for just the second time in 15 seasons.
Rowe said Trocheck "will be a prominent part of the Panthers for years to come."
The 22-year-old Trocheck has 37 goals and 46 assists in 146 NHL games. Smith, 25, has 150 points in 285 career games.
With Smith, Trocheck, All-Star defenseman Aaron Ekblad (who agreed to a $60 million extension on Friday) and forward Alexander Barkov (who last season signed a $35.4 million extension that starts to kick in this fall), the Panthers have committed nearly $150 million to four key parts of their young core.
"It shows that they really want to win," Trocheck said. "That makes us excited."
It's expected that forward Jonathan Huberdeau, who is entering the last year of his contract, will also be a candidate for a new deal with Florida before long.
Florida has added defensemen Keith Yandle, Mark Pysyk and Jason Demers, goalies James Reimer and Reto Berra, and forwards Colton Sceviour and Jonathan Marchessault in this offseason through free agency and trades. The Panthers also retained Jaromir Jagr, who turns 45 next season, on another one-year deal.