He played for the Wallabies for the first time in 2002 against England at Twickenham and was a nominee for the International Rugby Board Player of the Year in 2004.

Giteau attended St Edmund's College, Canberra,[1] which has produced other Wallabies including George Gregan, Matt Henjak and Ricky Stuart.

On 11 December 2010, Matt Giteau married Bianca Franklin, a former netball player with the Adelaide Thunderbirds.

In 2007, Giteau was selected for the Wallabies 2007 Rugby World Cup and 2008 squad and was first choice No.

In 2008, new Wallabies coach Robbie Deans selected Giteau as Australia's new fly-half, following the retirement of Stephen Larkham.

[citation needed] Giteau was also a part of the Wallabies' record loss that following week to South Africa 53–8.

Giteau was a key player for the Wallabies in reaching the Rugby World Cup final, but he copped a head knock in the opening stages of the final and was ruled out of the remainder of the match, which the Wallabies lost to the All Blacks 17–34.

On 15 May 2017, Giteau confirmed his move to Japan with Suntory Sungoliath in the Top League next season.

[7] In March 2021 Giteau joined his former Australia teammate, Adam Ashley-Cooper at the LA Giltinis for the 2021 Major League Rugby season.

[9] Giteau was named in the MLR team of the season with 98 points scored in 13 matches played.