Ballard, 27, helped Barrow to promotion in 2012, earning selection in the all-star team, before moving on to Swinton.
Hawks director of rugby Darren Williams said: “We realised we were a little short of outside backs with only three specialist wingers on the books and with doubts over the fitness of Lee Mapals and Jamaine Akaidere ahead of this weekend’s fixture, along with David March missing the early pre season games due to a thumb complaint, we were also lacking an established goal kicker.
“Andy ticks both boxes, is exceptionally quick who is an outstanding finisher with a keen eye for space. He is a quality addition who should be plying his trade at Championship level.”
Ballard scored 62 tries in four years with the Raiders, and has also previously played for Oldham, Salford and Wigan.
He said: “I can’t wait to get started and meet the boys, once I spoke to Darren who sold the club to me and Thomas Coyle had nothing but good things to say about the set up it was an easy decision to make.”