Montreal, he managed a new personal best of 9 goals and 12 assists in 69 games. While playing with the Canadiens over the course of the contract, Chiarot assumed an increasingly prominent role in their defense corps, notably participating in the team's deep run to the 2021 Stanley Cup Finals, where they lost to the Tampa Bay Lightning. He led the Canadiens in ice time during the playoffs. He later remarked "getting to the Finals is the pinnacle of what hockey is when you're playing for the Stanley Cup and it's down to two teams. I'll always be grateful that I had that experience because it's not one that everybody gets." Entering the final season of his contract, he became the subject of increasing speculation that he would be traded before the deadline in order to secure the Canadiens more picks in the 2022 NHL Entry Draft. Chiarot recorded 18 points in 54 games with the Canadiens, the last being an assist on the game-tying shorthanded goal in the final minute of the third period of a March 13 game against the Philadelphia Flyers, leading to a 4–3 Canadiens victory in overtime. On March 15, coach Martin St. Louis announced that he would sit out the remaining games in advance of the trade deadline to avoid injury. Florida Panthers On March 16, 2022, Chiarot was traded by the Canadiens to the Florida Panthers, for prospect Tyler Smilanic, a 2023 first-round pick, and a 2022 fourth-round pick. Following the trade, Chiarot remained in Montreal rather than joining the team on the road, and made his debut with the club on March 24 in a game against the Canadiens. He registered his first assist with the team in the game, contributing to a 4–3 Panthers victory. The Panthers won the Presidents' Trophy with the best regular season record in the NHL, and qualified for the 2022 Stanley Cup playoffs. Chiarot assumed a prominent role in the Panthers' defense during their first round series against the Washington Capitals, where they prevailed 4 games to 2, advancing to the second round for the first time in a quarter century. Chariot was fined for head-butting Tampa Bay Lightning forward Ross Colton in Game 1 of the second round. The Panthers were swept by the Lightning, bringing their playoffs to an end. Detroit Red Wings On July 13, 2022, Chiarot signed a four-year, $19 million contract