The 34-year-old defenseman was an unrestricted free agent. He scored 10 points (one goal, nine assists) in 39 regular-season games with the Vancouver Canucks and Winnipeg Jets last season and had one assist in three Stanley Cup Playoff games.
The Jets acquired Benn in a trade with the Canucks on April 12 for a sixth-round pick in the 2021 NHL Draft (forward Connor Lockhart).
Benn, who signed with the Dallas Stars as an undrafted free agent July 1, 2011, has scored 127 points (24 goals, 103 assists) in 556 regular-season games with the Stars, Montreal Canadiens, Canucks and Jets, and four assists in 23 playoff games.