The longest-serving City player in the club's tilt at a maiden championship, Atkinson's Perth signature was announced alongside nine-time Socceroo Andrew Nabbout.

"We are absolutely thrilled to have secured the services of two of the A-League's very best players in their respective positions," Perth football director Jacob Burns said.

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"A host of clubs both in Australia in overseas were vying to sign them. Nabbout is a proven goalscorer with World Cup experience whose pace and power excites fans.

"Atkinson is a similarly exciting and explosive talent who has just enjoyed a breakout year with Melbourne City.

"He can operate equally effectively on either side of the defence and given that he is still only 21, will continue to improve in the coming seasons."

Atkinson, who made 57 senior City appearances, was out of contract following Sunday's loss to Sydney.

"I've been at Melbourne City for five years and I've loved every moment of it," he said last week.

"So whatever happens at the end of this, it's just one of those things to think about after the grand final but I'd love to stay at Melbourne City."

A former Riverside Olympic junior, Atkinson first signed for City's youth team in 2016.

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