McKay played an integral role in Australia's second placing in the 2011 AFC Asian Cup notably with 30m cross to centre forward Harry Kewell.

[3][4] McKay was signed by NSL team the Brisbane Strikers in 2001, where he stayed until the conclusion of the 2003–04 National Soccer League season.

[7] It was reported after the match that a stirring speech by McKay at half-time in extra time boosted the Roar's morale sufficiently to unbelievably overcome a 2–0 deficit.

[14] On 22 February 2012, Rangers confirmed that they had agreed a fee with South Korean club Busan IPark for midfielder Matt McKay.

On 16 August 2006, McKay came on as a substitute for Australia in the 90th minute of the 2007 Asian Cup qualifying match against Kuwait at Sydney Football Stadium for his first Socceroo cap.

[19] McKay would have to wait until 28 January 2009 for his second cap, starting in Australia's 2011 Asian Cup qualifying match against Indonesia in Jakarta.

McKay was selected for the 2011 AFC Asian Cup squad by Holger Osieck,[20] and started in the team's pre-tournament friendly against the United Arab Emirates on 5 January 2011 in Al Ain.

[22] McKay retained his starting position for the semi-final against Uzbekistan, and was again a key player for Australia in the team's 6–0 win, setting up three goals and being awarded man of the match.

[23] Due to McKay's excellent form, he was retained in the starting XI by Osieck for the Asian Cup Final, playing the full 120 minutes as the Socceroos lost 1–0 to Japan.