Knight is entering the final year of his entry-level deal and this new contract will begin in the 2023-24 season.
Knight, 21, posted a 19-9-3 record as a rookie in 2021-22 with a .908 save percentage and two shutouts.
"Spencer is a phenomenal goaltender, as well as an exceptional athlete and person," general manager Bill Zito said in a statement. "He has thrived in his professional career, dedicating himself to his training through his first two seasons with our organization. With this extension, we are excited about the present and future of Panthers goaltending."