The 23-year-old left Celtic Park after failing to break into the first team, spending last season on loan at Lincoln.
Kilmarnock boss Kenny Shiels told STV: "Ben has signed on a short-term contract until January.
"It's a good opportunity for him to re-establish his career and get back to the player that he was.
"He couldn't be in better hands being at Kilmarnock. I think we're a club where we develop players to help them become better, which in turn will help the team to get better results. That's what we're about.
"Ben has got good movement, good work-rate and his touch is good. He has a good understanding of linking in the final third."