Horachek took over after Kevin Dineen was fired on Nov. 8. The Panthers posted a 26-36-4 record under Horachek and finished the season with the second-lowest point total (66) in the NHL.
"Peter worked very diligently since taking over as interim head coach in November, but at this time we feel that a fresh approach and a new direction is needed behind our bench," Panthers GM Dale Tallon said in a statement. "We will immediately begin an extensive search for a new and experienced coach for our franchise, who will guide the Panthers to future success."
The 54-year-old Horachek was promoted from the Panthers' San Antonio AHL affiliate to take the job when Florida started poorly under Dineen. After Horachek arrived, the Panthers responded by going 10-8-1 but then struggled near the end of the season. They posted a 6-14-1 record in their final 21 games and finished next-to-last in the Atlantic Division.
The franchise, which has missed the playoffs in 12 of the past 13 seasons, has now dismissed three coaches in the past three years. Tallon said a search will begin immediately for a new coach.