It was announced on 22 May 2013, that Halloran had requested a move to Fortuna Düsseldorf (German 2. Bundesliga), a request that was approved by Brisbane Roar. The transfer amount was said to be around $400,000. On 7 October 2013, Halloran made his debut for Fortuna Düsseldorf against Greuther Fürth. Ben would play the entire match on the right wing in the 2–1 win. Halloran scored his first goal for Düsseldorf's first team in his sixth appearance, and in the 70th minute, with the goal equalizing the score and snatching a point for his team.