Carlsson signed a contract in early July that will pay him an average of $18 million over five years. Celebrini's new contract will give him a salary of $18.8 million per year.
"I couldn't be happier to sign an extension. My teammates and I are ready to take a step towards the next step, winning the Stanley Cup," Celebrini told the club's website.
The 20-year-old Celebrini finished fourth in the NHL's scoring race with 115 points, 45 goals and 70 assists last season. His new contract runs through the fall of 2027.
Celebrini was part of Canada's Olympic team that won a silver medal in Milan this spring.
