Lia, 34, moves west after plying his trade for the Reds across the past three seasons where he scored three goals in 43 appearances for United.
An A-League veteran of more than 250 games, Lia expressed his gratitude to Adelaide in the wake of his move.
“I want to thank everyone at Adelaide United for welcoming me and making me feel comfortable since I joined the club,” Lia said.
“To win two FFA Cups is something I’ll never forget and I’m proud to be part of this club’s successful history.
“I’ve loved my time in South Australia and wish the boys the best for the rest of the season.”
Expected to patch a hole in the Glory defence caused by the injured Dino Djulbic, the versatile midfielder is champing at the bit to throw on the purple jersey.
“I’m really looking forward to being part of what I think is a special group," Lia said.
“It’s a team that will obviously challenge for the league again and with an Asian Champions League campaign coming up, I’m hoping to help in any way I can.”
Currently sitting in third place on the A-League ladder, Perth has tasted success in all five of its past hit-outs in the competition and will hope the former Ibis can contribute to its current vein of form.
“Vince brings a wealth of experience and versatility, plus a winning mentality and has been a consummate professional throughout his career,” Glory football director Jacob Burns said.
“He will provide great competition and depth to our squad during what will be a testing time physically as we look to compete both domestically and in Asia.”
While the switch to the fourth A-League club of his career may come as no surprise, Tatura faithful can only cross their fingers and hope Lia’s next move comes in the form of a return to Ibisland.