He currently plays for Hanazono Liners in Japan, and is a former player for the Queensland Reds and the Melbourne Rebels in the Super Rugby competition in Australia.

[9] In the first year of his ascendance, his team tied for the Queensland GPS Premiership with Brisbane State High School in 2005. Cooper played in all the age group rugby union and league sides in Waikato.

[13] Cooper joined the ARU-funded high-performance program with the national talent squad, and signed with the Queensland Reds for the 2007 Super 14 season.

[17] It was reported by The Sunday Mail early 2008 that the New Zealand Rugby Union showed interest and had held preliminary talks with Cooper's management team after he would be off contract at season's end with Queensland.

[19] Cooper performed a try assist after a chip kick to Morgan Turinui in the 72nd minute, securing their first bonus-point victory in four years.

[20] Cooper was amongst seven Super 14 players included in the Australian national under-20 side after coach Brian Melrose confirmed the team naming for the inaugural 2008 IRB Junior World Championships in June.

Cooper was involved in a touchline fight between Federico Pucciariello after tussling into the advertising boards and needed to be separated by colleagues and verbally warned by referee Chris White.

After repeating another near bottom of the table finish, Cooper was one of just four players and the only member of the backline to appear in all thirteen matches during the Reds 2009 Super 14 campaign.

Cooper stood out on tour and earned praise from former Welsh great Barry John after a victory over Wales at Millennium Stadium.

[30] Playing at fly-half in the Wallabies' 1st Tri-Nations Series Test against South Africa, Cooper was yellow-carded during the game for a dangerous tackle on Morne Steyn.

[32][33] Cooper was selected for the Wallabies for Rugby World Cup 2011 in New Zealand, where he played all but one of Australia's matches, starting all games at flyhalf.

[citation needed] In Round 18, Cooper was yellow-carded and placed on report for a high tackle on former Reds and current Wallabies teammate Berrick Barnes.

Cooper apologised to the Toulon fanbase for "extended negotiations" allowing him to be released if called to the Australian Sevens team for the Olympics.

Cooper joined former Wallaby teammates Matt Giteau and Drew Mitchell, James O'Connor and Sales Ma'afu at the French club.

Cooper joined the Australian 7s squad in the lead-up to the 2016 Olympic Games, commencing with the Sydney leg of the World Rugby Sevens Series.

Cooper was selected for the Wallabies squad for the June tests against Fiji, Scotland and Italy, with Bernard Foley preferred in the starting role.

The two wins and upset loss against Scotland would become Cooper's last appearance in a test jersey until 2021 as he was snubbed by Cheika for the 2017 Spring Tour, instead being selected to captain Alan Jones' Barbarians FC side, managing a free-flowing style of football which caught the Wallabies by surprise, the Wallabies would go on to claim a narrow 31–28 victory in Sydney.

It was revealed new head coach Brad Thorn told Cooper that "he was the fifth-choice fly-half and was no longer part of his plans" for the franchise and would not be needed at training.

Meanwhile, Cooper spent the majority of 2018 playing for Souths, captaining the Queensland Premier Rugby side to a knockout semi-final in August 2018.

In 2018, Cooper and former Reds teammates Karmichael Hunt and James Slipper were named in a 36-man squad selection for NRC side Brisbane City.

[47][48][49] After a hot start to the season, Rebels had a poorer back end and finished 11th overall, missing out on a finals wild card spot.

Subsequently, Cooper was notably absent from Wallabies squads for the test season with Lealiifano expectedly ahead of him given the Brumbies run to the finals, however Michael Cheika preferred Waratahs Bernard Foley and Kurtley Beale as backup options ahead of him as well as Rebels teammate Matt To'omua, who interestingly rarely featured at flyhalf for the Rebels or Leicester.

In 2021, prior to the first test of the Bledisloe Cup, rumours had circled that Cooper would be called into the Wallabies squad a result of Australia's COVID restrictions and lack of form among the Australian flyhalves during the Super Rugby AU and Trans Tasman season.

On July 25, it was formally announced that Cooper was named in the squad, alongside former Reds teammate Duncan Paia'aua as newcomers to Dave Rennie's test setup.

[51] In round 4 of the 2021 Rugby Championship, Cooper was selected by Rennie to start at his preferred flyhalf ahead of incumbent Lolesio, who was absent from the matchday 23 altogether.

[65] On 14 September 2021, after Cooper had rejoined the Wallabies and helped win a 2021 Rugby Championship match against the Springboks, Australian Immigration Minister Alex Hawke announced that greater flexibility for residency requirements for citizenship would in future be allowed for the "most highly distinguished prospective Australians" due to their "unique work and travel demands", although he didn't mention Cooper explicitly.

[32][33] In September, Cooper tweeted comments on the Wallabies’ set-up, which included criticising the defensive style and lack of player input under coach Robbie Deans, inadequate training and recovery facilities, and a "toxic environment".