The 32-year-old Canadian has made 218 appearances in the world’s top league, his most recent stint being at the Winnipeg Jets between 2013-15 following spells at the Florida Panthers and the Los Angeles Kings.
He has since played in several top leagues in Europe, including Sweden, Finland and Germany, as well as a year in the KHL with Barys Astana.
Now, Steelers’ head coach Aaron Fox has convinced him his future lies in the UK.
“My conversations with Aaron Fox were good, I liked his vision and philosophy on how the game should be played,” said Ellerby.
“We have had great times since moving over to Europe, seen some great places and met some incredible people. We are excited about extending that journey to the UK, the idea of playing in a English-speaking country was a draw for sure.”
Fox believes his latest signing will bring a welcome two-way game to the back-end.
“Keaton is a big bodied D-man who skates extremely well for his size,” said Fox. “He can play a physical game when needed and is extremely sound in his own end.
“Because he skates so well I feel like he will bring some two way offense to our group as well as I like our D to play fast and join the play as much as possible.”