Simmons left his run late as the only player to re-sign with the ARU this year, but the promising forward's commitment is a major boost to his Super Rugby outfit the Reds and the national side.
The 22-year-old joins the 22 players who re-signed with the ARU in 2011, providing stability for the Australian team to build on last year's Tri Nations triumph and indifferent World Cup campaign.
A product of Theodore in country Queensland, Simmons first appeared for the Reds in Super Rugby during the 2009 season, before making his run-on debut the following year.
Simmons also stepped into the international arena in 2010, firstly for the Australian Barbarians during the two-match midweek series against the touring England, and then for the Wallabies in the Tri Nations.
Simmons made his Test debut on his home ground at Suncorp Stadium in Brisbane, during Australia's 30-13 win over against South Africa.
He has subsequently cemented his place as a regular member of the Wallabies squad, securing 16 Test caps as well as a run-on appearance against the Barbarians during Australia's recent spring tour of Europe.
Simmons played in 10 of the Wallabies' 13 Tests last year and was part of the squad that defeated the All Blacks in Brisbane to claim Australia's first Tri Nations title in 10 years.
Wallabies coach Robbie Deans said he was pleased Simmons had decided to recommit to Australian rugby for another two years.
"It is encouraging ... Players always have choice. Rob is a player who has a big future and is working hard towards that so it's pleasing he sees his future playing in Australia taking the game here forward," said Deans.
"The fact that we have been able to keep our core group of Wallabies together is a positive sign for the direction the team is headed in, and the players commitment to that."
Simmons, who featured in six of the Wallabies' seven World Cup games last year, said he was excited at what the future held for him in Australia.
"The last two years have been great, being a part of the Wallabies, and I am really looking forward to the challenges of the next two years," Simmons said.
"My focus is currently on the Reds and starting the Super Rugby season off on the right foot, but I am also very keen to get back in the gold jersey and represent my country again.
"When I look at the other players that have re-signed in
the last 12 months and what we achieved last year I think there is
opportunity for us to enjoy some more success in the coming years and I
am very keen to be a part of and contribute to that success."