The 25-year old, who started his career in Western Australia, has departed Chinese Super League club Guangzhou R&F to sign a deal with the Glory which will keep him in the A-League until at least the end of the 2014/15 season.
Regarding the addition of the former Blackburn Rovers, North Queensland Fury and Central Coast Mariners man, Glory interim head coach Kenny Lowe said: "Rostyn is a fantastic player who is composed on the ball and good in the air.
"We're very excited to have such and an experienced, dynamic and powerful midfielder join our squad.
"It's also great to have another WA player returning home and is further proof we are setting up the right foundations at Perth Glory.
"We now have an abundance of quality in the midfield area so it creates great competition for places in the team."
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