The 28-year-old forward was placed on waivers by the New Jersey Devils on April 1 after he scored five points (two goals, three assists) in 20 games this season.
"Nikita is a highly skilled and creative forward who plays the game with great speed and playmaking ability," Panthers general manager Bill Zito said. "He has proven himself to be a tremendous offensive talent throughout his career. We are thrilled for Nikita to join the Panthers and look forward to what he can add to our team."
Gusev was traded to the Devils by the Vegas Golden Knights and signed a two-year, $9 million contract with New Jersey on July 29, 2019. He has scored 49 points (15 goals, 34 assists) in 86 NHL games after playing nine seasons in the Kontinental Hockey League.
"Highly skilled," Florida coach Joel Quenneville said Monday. "Power-play guy. Can score. Can play with good players. He gets an opportunity maybe right off the bat. We'll see how he takes care of it or handles it and then we'll find out. You've got some good options with him in the lineup for sure."
Defenseman Brandon Montour was traded to Florida by the Buffalo Sabres on Saturday for a third-round pick in the 2021 NHL Draft. The 27-year-old has scored 14 points (five goals, nine assists) in 38 games and can become an unrestricted free agent after the season.
The Panthers (26-12-4) have lost three in a row and are third in the eight-team Discover Central Division, two points behind the Carolina Hurricanes and Tampa Bay Lightning. The top four teams will make the Stanley Cup Playoffs; Florida plays at the Dallas Stars on Tuesday (8:30 p.m. ET; ESPN+, BSSW+, BSFL, NHL.TV).
Quenneville said Gusev and Montour each is expected to be in the lineup when the Panthers visit the Lightning on Thursday.
NHL.com independent correspondent Alain Poupart contributed to this report
