Under coach Ange Postecoglou, McKay captained the Roar to the club’s first title in 2010/11, finishing the season on a 28-game unbeaten streak.
In that season, he was named PFA Player of the Year.
His teammates would lengthen that run to an Australian-record 36 matches as he pursued an overseas career, but McKay returned to help Brisbane win another double in 2013/14 under Mike Mulvey.
He’s continued on at the Roar through the club’s downturn in fortunes and has decided against playing on next year.
“I’m grateful for everything football has given me,” McKay said.
“I’ve had an enjoyable career with plenty of highs and lows, but I’ve always had a smile on my face and that’s what’s made it for me.”
McKay also enjoyed success in the Socceroos set-up, most notably under his former club boss Postecoglou.
He travelled to Brazil as part of Australia’s 2014 World Cup team and helped the Socceroos win a first major trophy – the Asian Cup – in 2015.
“I’ve always tried my hardest and I think that’s what has made my career last as long as it it has – I’ve always given my all,” McKay said.
“I was there from day one at the Roar and played with some immense players with a great work ethic, which has been really special.”
McKay has two matches to finish his A-League career, both on home soil.
The Roar face Newcastle on Saturday and then Adelaide United on Anzac Day, with tributes planned for the foundation A-League player.