St George Illawarra Dragons lock forward Shaun Timmins has been a surprise omission from the upcoming Tri-Nations series.
Panthers front rower Trent Waterhouse was also overlooked.
Cooper has a had a meteoric rise in 2004, making his representative debut in this year's City-Country Origin game before playing for NSW.
"It was a good shock. It means the world to me. I have been playing football since I was four. When you're little this is what you dream of, to play for your country." Cooper said.
Meanwhile four Bulldogs have been named in the squad with Willie Mason, Andrew Ryan, Mark O'Meley and Willie Tonga all being included after playing in Sunday's 16-13 grand final win over the Sydney Roosters.
A surprise selection was Brisbane's Tonie Carroll who was rewarded after a solid season with the Broncos. Cowboys fullback Matt Bowen was also given the nod.
Panthers winger Luke Rooney is amongst seven debutantes joining Ryan, O'Meley, Tonga, Bowen, Carroll and Cooper.
Full Kangaroos squad: Shaun Berrigan, Matt Bowen, Danny Buderus (v-capt), Tonie Carroll, Petero Civoniceva, Matt Cooper, Michael Crocker, Craig Fitzgibbon, Craig Gower, Scott Hill, Nathan Hindmarsh, Ben Kennedy, Brett Kimmorley, Darren Lockyer (capt), Willie Mason, Anthony Minichiello, Mark O'Meley, Luke Rooney, Andrew Ryan, Jason Ryles, Matt Sing, Brent Tate, Willie Tonga, Shane Webcke, Craig Wing.
The tournament begins in mid October 2004 in New Zealand. The Australian Kangaroos and the New Zealand Kiwis will match up first. They then fly to the UK for all subsequent matches where the Great Britain & Ireland Lions await them.
Sat Oct 16: New Zealand v Australia, in New Zealand Sat Oct 23: Australia v New Zealand, Loftus Road, London Sat Oct 30: Great Britain v Australia, City of Manchester Stadium Sat Nov 6: Great Britain v New Zealand, McAlpine Stadium, Huddersfield Sat Nov 13: Great Britain v Australia, JJB Stadium, Wigan Sat Nov 20: Great Britain v New Zealand, KC Stadium, Hull Sat Nov 27: Gillette Tri-Nations Final, Elland Road, LeedsLike