Peter Siddle, the famous cricketer who recently announced his retirement belongs to which country?

The veteran bowler of Australian Cricket team, Peter Siddle announced his retirement from international cricket recently. He has represented the Australian Cricket team for 11 years with the last match being the fifth Test of the Ashes in England, played this year. Siddle is the 13th highest wicket-taker in Tests for Australia, including his famous hat-trick against England in Brisbane in 2010. He has taken 221 wickets in the 67 test matched he played for Cricket Australia.