Queenslander Meehan, who left Bath last year after a five-year stint at The Rec, joins a set-up in Perth that includes head coach Michael Foley and newly-appointed strategist Phillip Fowler.
Foley is delighted to have the experience of Meehan on board.
He said: "We said that we were going to recruit the best attack coach available and that's exactly what we've done. With our focus on attacking and dynamic rugby, we're fortunate to bring in someone with the experience and expertise of Steve (Meehan).
"His record at Stade Francais and Bath speaks for itself; he was able to implement a game style that players loved playing, that fans loved watching and that ultimately brought success. We have a similar goal for the side in 2013."
Meehan led Bath to their first trophy for 10 years in 2008 when he guided the side to European Challenge Cup glory, secured by victory over Worcester.