Born and raised in Darien, Connecticut, Knight became a goaltender after watching Henrik Lundqvist play for the New York Rangers.

He spent one year at Darien High School and another at Avon Old Farms before joining the USA Hockey National Team Development Program in 2018.

A fan of the New York Rangers of the National Hockey League, Knight was partially motivated to goaltend by watching Henrik Lundqvist.

[2] He attended Darien High School for one year before transferring to Avon Old Farms,[3] where he became the hockey team's starting goaltender in his first season.

[4] Playing alongside Trevor Zegras, Knight posted a 1.89 goals against average (GAA) and .935 save percentage (SV%) at Avon in 22 games as a sophomore.

[5][6] Knight left Avon Old Farms after the 2016–17 season to join the USA Hockey National Team Development Program (NTDP) in Michigan.

[16] The Eagles won the Hockey East regular-season title with their 4–1 defeat of rival Boston University on February 29, 2020.

[21][22] Knight and his teammate Matthew Boldy both received Hockey East Player of the Week Honors for their two-game sweep of the Providence Friars on December 4 and 5, 2020.

[23] He was named the Hockey East Goaltender of the Month as a combined award for November and December after beginning the season 4–0–0 with a .955 SV% and 1.50 GAA.

Facing elimination in Game 5 of the best-of-seven series, coach Joel Quenneville gave Knight the start over Sergei Bobrovsky and Chris Driedger.

[41] The Panthers lost Driedger to the Seattle Kraken in the 2021 NHL Expansion Draft,[42] and so they entered the 2021–22 season with a goaltending tandem of Bobrovsky and Knight.

[44] On January 29, 2022, the Panthers sent Knight to the Charlotte Checkers, their American Hockey League (AHL) affiliate, to "keep his cadence" and continue to receive playing time through the NHL All-Star Game break.

[48] He entered the 2022 Stanley Cup playoffs as a backup to Bobrovsky, not appearing at all in the Panthers' first-round series against the Washington Capitals.

[52] The team was eliminated in the quarterfinals after a 1–0 loss to Finland, but Knight personally played well, with two wins, a 2.49 GAA, and .913 SV% in the four games in which he appeared.

Knight finished the tournament with a 5–1–0 record, 1.63 GAA, .940 SV%, and three shutouts, and Team USA named him the Player of the Game for the gold medal match.