Ellerby, who is from Strathmore, Alberta, less than an hour east of Calgary, recorded three assists for the Los Angeles Kings last season in 35 games played. He also played nine games last season with the Florida Panthers.
Ellerby, who was drafted by the Panthers with their first pick, tenth overall in the 2007 National Hockey League Entry Draft, played four seasons with Florida before being traded to Los Angeles for a fifth round draft choice in the 2013 National Hockey League Entry Draft.
The Jets were in need of a defenseman because of the injuries to rookie blueliner Jacob Trouba (upper body), Paul Postma (blood clot in his leg) and Mark Stuart (hip).
The Jets next play on Saturday as they host the Chicago Blackhawks. The game has meaning because it will be the first time in Blackhawks' star Jonathan Toews's career he will play a National Hockey League game in his hometown of Winnipeg.