Carter stays but Fardy moves to Pro12
The 27-year old made his Wallabies debut in 2014 against France but last featured in the Test arena against England in Melbourne last year.
Now with 13 Test caps, Carter is also the co-captain in Canberra alongside Christian Lealiifano.
"We have an exciting team here at the Brumbies with an excellent blend of experienced heads alongside some top-quality youngsters and I am excited to be part of the continuing success of the franchise," Carter said.
"The Brumbies are very special to me and have been a major part of my rugby career and it’s great to be able to be settled and in an environment, I know very well. There are lots of positive vibes around the club and I am looking forward to playing my part.
"Playing for the Wallabies was also a major motivator to re-sign and I’m excited at the prospect of pulling on the Gold jersey again and pushing hard to earn a spot at the World Cup in 2019,"
Wallabies coach Michael Cheika said: "Sam didn’t get as much game time for the Wallabies as he would have liked last year but he showed great character in how hard he worked on the training field.
"For Sam to knock back overseas offers and stay in Australia also shows how seriously he’s taking his new role as captain at the Brumbies and that he’s not a one-and-out type of guy," Cheika said.
The son of former Wallaby, David Carter, Sam is a product of Rugby nursery Scots College in Sydney but originally hails from Quirindi in country New South Wales.
Meanwhile, back row Scott Fardy has decided to move on from the Brumbies and will join Pro12 side Leinster at the end of the season.
Fardy made his debut for the Brumbies in 2012 against the Force in Canberra and has over eighty Super Rugby caps to his name.
"Scott has been a fantastic player for the Brumbies during his spell with the franchise," CEO Michael Thomson commented.
"Whilst we are obviously disappointed that Scott has decided to move on, we thank him for his service to the club and wish him all the best for the future."
Speaking to Leinsterrugby, Fardy said, "I am delighted to be joining Leinster Rugby a club with a rich heritage and a proud tradition.
"I’ve enjoyed hugely my time with the Brumbies since making my debut in 2012 but this is an exciting opportunity for me to challenge myself in a new club and a different country.
"I am very grateful to the Brumbies and the Australian fans for all the support over the years and I am committed to seeing out the Super Rugby season in a positive manner and that continues this weekend against the Sharks,"
