The deal was announced early in the NHL's free-agent signing season.
In 72 games for the Panthers last season, Booth recorded 31 goals and 29 assists, both career highs. The 24-year-old Michigan native also became the sixth player in franchise history to score at least 30 goals. He led the team with 246 shots.
"I'm really pumped to be in the organization," Booth said. "This is one of the best days of my life."
Florida's third choice (53rd overall) in the 2004 draft, Booth has 56 goals and 54 assists in his 193 NHL games. Booth, who has been invited to attend USA Hockey's Olympic orientation camp next month, remains part of a hockey club that hasn't won a playoff series since 1996 or a playoff game since 1997.
"We're just delighted," assistant general manager Randy Sexton said. "I think David embodies everything that we believe is the ideal Panther. ... For us, it was critical to get this guy signed."
Defenseman Ville Koistinen also agreed to terms on a two-year deal on Wednesday and the Panthers added goalie Scott Clemmensen, who agreed to a three-year contract. Goalie Craig Anderson, who had spent the past three seasons with the Panthers, signed a two-year contract with the Colorado Avalanche earlier in the day.
"He's going to do a great job for us," Sexton said. "We don't think we'll skip a beat with Anderson gone and Scott Clemmensen here."
In 40 games with the New Jersey Devils last season, Clemmensen, 32, was 25-13-1 with a 2.39 goals-against average and a .917 save percentage. His signing casts some doubt on whether Tomas Vokoun will be Florida's top goalie next season.
"We fully expect a real competitive situation for the starting position," Sexton said.
After Florida's deal with the 28-year-old Koistinen was announced, Sexton said the chances the team would also sign defenseman Jordan Leopold were slim. Leopold, a free agent, had his exclusive negotiating rights traded to the Panthers on Saturday for the rights to defenseman Jay Bouwmeester, who signed a multiyear contract with Calgary on Tuesday.
"I wouldn't say it's out of the question," Sexton said, "but I'd say it's remote."
The Panthers also announced that right wing Radek Dvorak has agreed to terms on a two-year deal. Dvorak, 32, had 15 goals and 21 assists during the 2008-09 season.
ST. LOUIS (AP) -- The St. Louis Blues, seeking to add depth at the goaltender position, have signed free-agent Ty Conklin.
Terms of the deal announced Wednesday were not disclosed.
The 33-year-old Conklin played in 40 games for Detroit last season, going 25-11-2 with a 2.51 goals against average and a .909 save percentage. His six shutouts tied for the sixth-most in the NHL.
The Anchorage, Alaska, native is 73-43-14 with a 2.58 goals against average and .909 save percentage in six seasons. He was originally signed by Edmonton as an undrafted free agent in 2001.
Chris Mason seized the starting job in midseason from Manny Legace and started the final 33 regular-season games and all four playoff games for the Blues.