Panthers general manager Dale Tallon made the announcement Tuesday, saying the dismissal was effective immediately. Horachek replaced Kevin Dineen as Panthers' coach on Nov. 8, and Florida went 26-36-4 under him.
Horachek had been the coach of Florida's AHL affiliate in San Antonio before being summoned to lead the Panthers.
Florida finished with the second-lowest point total in the NHL this season and missed the playoffs for the 12th time in 13 seasons. The Panthers last won a playoff series in 1996, the year they lost to Colorado in the Stanley Cup finals.