Born in Plana, Czech Republic, Kahun grew up in Germany before arriving in North America in 2012. He played two seasons with Sudbury of the Ontario Hockey League.

Kahun went undrafted and played the next five seasons in Germany, including four with EHC Munchen in the Deutsche Eishockey Liga. In 2017-18, he scored 41 points (12 goals, 29 assists) in 42 games and also helped Germany finish second at the 2018 Sochi Olympics, where he scored five points (two goals, three assists) in seven games.

That caught the attention of the Chicago Blackhawks, who signed Kahun as a free agent on May 21, 2018.

Kahun made an immediate impact in Chicago in 2018-19 and tied for seventh among NHL rookies with 37 points (13 goals, 24 assists) in 82 games.

He was traded after the season to the Pittsburgh Penguins, along with a fifth-round pick in the 2019 NHL Draft, for defenseman Olli Maatta on June 15, 2019.

During his first season with Pittsburgh, Kahun scored 27 points (10 goals, 17 assists) in 50 games, but he was traded for the second time in less than a year on Feb. 24, 2020, this time to the Sabres for Conor Sheary and Evan Rodrigues.

Kahun scored four points (two goals, two assists) in six games for the Sabres before the NHL paused the 2019-20 season on March 12 due to concerns surrounding the coronavirus.

NOTES & TRANSACTIONS

• Signed as a free agent by Chicago, May 21, 2018.
• Traded to Pittsburgh by Chicago with a 5th-round pick in 2019 NHL Draft for Olli Maatta, June 15, 2019.
• Traded to Buffalo by Pittsburgh for Conor Sheary and Evan Rodrigues, February 24, 2020.
• Signed as a free agent by Edmonton, November 2, 2020.