On October 7, 2020, the Tampa Bay Lightning selected Thompson with the 93rd overall pick in the third round of the 2020 NHL Entry Draft.

Thompson went there while waiting for the Ontario Hockey League (OHL) season to resume due to the COVID-19 pause.

He also appeared in one game with Tampa Bay' American Hockey League (AHL) affiliate, the Syracuse Crunch.

[4] On January 6, 2024, Thompson made his NHL debut with the Lightning against the Boston Bruins at TD Garden.

[5] On March 7, Thompson along with a 2024 third-round draft pick was traded to the San Jose Sharks in exchange for Anthony Duclair.