An undrafted player, Benn played for the Dallas Stars, Montreal Canadiens, Vancouver Canucks, Winnipeg Jets, Minnesota Wild, Toronto Maple Leafs and Brynäs IF.

[5] In the midst of the 2016–17 season, Benn's tenure with the Stars came to an end after seven years, as he was traded prior to the deadline to the Montreal Canadiens in exchange for Greg Pateryn and a fourth-round draft pick in 2017 on February 27, 2017.

[8]On July 1, 2019, Benn returned to his home province, signing as a free agent to a two-year, $4 million contract with the Vancouver Canucks.

[10] In his final year under contract with the Canucks in the 2020–21 season, Benn was dealt at the trade deadline to the Winnipeg Jets for a 2021 sixth-round pick on April 12, 2021.

[11] In the closing stages of the regular season Benn, was competing with Logan Stanley and Ville Heinola for playing time, registering one assist through eight games.

[17] After missing time with a groin injury, Benn played in his first game with the Maple Leafs on November 12, scoring his first goal with the team.