Cooper was born in Auckland, but moved with his family to Tokoroa at a young age. He attended Forest View High School before moving to Brisbane, Australia, as a 13-year-old in 2001.
In Brisbane, Cooper attended Springwood State High School before winning a scholarship to Anglican Church Grammar School (Churchie), where he starred for the 1st XV rugby team in 2005 and 2006. Churchie shared the Queensland GPS Premiership with Brisbane State High School in 2005.
Cooper was selected for the Australian Schoolboys in both 2005 and 2006. He played Fly-half and won nine schoolboy caps, which was the equal record at that time.
Cooper joined the ARU-funded high performance program with the National Talent Squad, and signed with the Queensland Reds for the 2007 season.
Cooper made his debut for the Reds in Round 2 of the 2007 season in Super 14, against the Crusaders at Jade Stadium, Christchurch. The Reds went on to lose the game 33–22.
2008 saw the Reds win 40–8 in a huge upset against the Bulls in Cooper's first start of the 2008 season. In November 2008 Cooper made his international debut against Italy, coming off the bench to scoring the winning try in a 30–20 win.
In 2009, Cooper featured in all of the Reds Super 14 games scoring 27 points (4 tries, 2 conversion goals and a penalty goal). He also featured in 8 Tests for the Wallabies playing at Inside Centre.
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. Later he was suspended from two Tests against New Zealand, the Bledisloe Cup clashes in Melbourne and Christchurch. He returned from suspension to face South Africa in Pretoria and Bloemfontein. He featured in the final Tri-Nations clash against the All Blacks in a 22–23 loss at ANZ Stadium in Sydney.
Cooper took part in all of the Wallabies' Spring Tour games, playing at flyhalf.
In 2011 Cooper signed with player agent Khoder Nasser.
In 2011, the Queensland Reds won the inaugural Super Rugby title, with Cooper featuring prominently and kicking most of their goals.
Cooper played in all of the Wallabies' Tri-Nations games. When James O'Connor was suspended from the deciding Tri-Nations test at Suncorp Stadium against the All Blacks, Cooper took over the kicking duties in a 25–20 win, securing Australia's only Tri-Nations title since 2001 in the final edition of the competition.
Cooper was selected for the Wallabies for Rugby World Cup 2011 in New Zealand. Starting all games at flyhalf, Cooper was booed by New Zealand crowds because he had earlier used his knee to smash the face of New Zealand captain Richie McCaw. Coach, Robbie Deans, through his experience with the judiciary, had been able to get him off.
Cooper was selected for the third-place playoff at Eden Park against Wales. Cooper set up the opening try before succumbing to an anterior cruciate ligament (ACL) injury that later ruled him out of the opening rounds of the Reds' title defence in the 2012 Super Rugby season.
In mid-2012, while recovering from the knee injury, Cooper signed a three-year deal to stay with the Reds through to 2015. Cooper's return from the injury came in Round 13 of the 2012 Super Rugby season against the Lions.
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 was later given a one-week suspension, causing him to miss the elimination-final against the Sharks, which the Reds lost 17-30.
In December 2012, Cooper agreed to a two-year contract extension with the ARU.
In 2013, Cooper played in all of the Reds' Super Rugby games. After the sacking of Deans as Wallabies coach and his replacement by former Reds coach Ewen McKenzie, Cooper made his first Wallabies appearance after a long absence in the first test of the 2013 Rugby Championship, coming off the bench for the final 20 minutes in a losing effort against the All Blacks. He featured in the starting 15 at flyhalf for the rest of the Rugby Championship.
In the Wallabies clash with the All Blacks at Forsyth Barr Stadium in Dunedin on 19 October, Cooper six goals from six attempts, an additional drop goal, made three try-saving tackles and two line-breaks, and set up a try for team-mate Adam Ashley-Cooper.
At the end of October, Cooper was named as vice-captain for the Cook Cup test against England. Under coach Ewen McKenzie he featured in all of the Wallabies' European spring tour games.
On 7 March 2014, Cooper broke Elton Flatley's record of 629 points, as well as the all-time Queensland Red's point-scoring record in the Reds' 43–33 win over South Africa's Cheetahs at Suncorp Stadium.
On 5 May 2014, Cooper received his 100th Super Rugby cap for the Reds in a match against the Auckland Blues at Eden Park. On 17 May, he was ruled out for the rest of the Super Rugby season following a shoulder injury against the Melbourne Rebels in round 14. He later underwent shoulder and hip surgery. After recovering from his injury, Cooper was named in the Wallabies' 32-man squad for the third Bledisloe Cup match against New Zealand at Suncorp Stadium.
On 21 April 2015, it was rumoured that Cooper had committed to a two-year deal with French Top 14 side Toulon. In July 2015 it was revealed that Cooper had turned down the deal and re-committed to the ARU in order to be part of the Rio 2016 sevens team.
On November 3, Cooper was 'unveiled' to the media as a member of the RC Toulon roster for the 2015-16 season. 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.
In his debut against Montpellier, Cooper helped set up multiple tries.
It was confirmed that Cooper would be joining the Australian 7s set-up for the 2016 Olympic Games, commencing with the Sydney leg of the IRB Sevens. Cooper scored his first try for the Australian sevens team on 6 March 2016 in the team's 36-7 win against England. However, Cooper was later dropped from the squad in May 2016. Cooper claimed he was dropped because he did not hold an Australian passport at the time as citizenship of a country is required to represent that country in an Olympics.
In November 2012, Cooper announced he would box on the undercard of friend Sonny Bill Williams' bout on 8 February 2013. He fought as a cruiserweight against Muay Thai veteran Barry Dunnett, winning by first-round knockout.
On 29 January 2014, Cooper fought 40-year-old Warren Tresidder on the undercard of the Anthony Mundine bout in Brisbane. Tresidder had 25 years of cage fighting experience at the time. Cooper went on to win with a 4th-round TKO.
On 31 January 2015, Cooper was due to fight on the undercard of Sonny Bill Williams's bout against Chauncy Welliver. However, he was later forced to pull out.
Cooper was selected for the Wallabies in the 2011 World Cup. However, he failed to match his form for the Reds.
In the bronze final against Wales at Eden Park in Auckland, New Zealand, Cooper showed early signs of returning to form by setting up the opening try to Berrick Barnes. But in the 20th minute of the game, he left the field with an ACL knee injury. This also forced him to miss the first 12 weeks of the 2012 Super Rugby season.
Cooper grew up playing rugby league with Shaun Kenny-Dowall and even came close to joining the NRL's Melbourne Storm in 2008. In August 2010 Cooper was rumoured to be considering a switch to rugby league and playing for the Parramatta Eels in the 2011 NRL season. This would have meant Cooper sacrificing his Wallabies' position. A figure of $850,000 was speculated, and Parramatta reportedly offered Cooper $1.5 million over three years. The issue was resolved in September when Cooper signed a one-year deal with the Australian Rugby Union. He said, even though he found the Parramatta offer flattering, he still saw his future in rugby union. For 2011 he wanted to continue with the Reds, and hoped to continue with the Wallabies and represent Australia at the 2011 Rugby World Cup.
Cooper is the cousin of Scotland international player and 2013 British & Irish Lion Sean Maitland and is the cousin of Cheyenne Campbell. Cooper is currently in a relationship with Australian model Laura Dundovic.
In December 2009, Cooper was charged with burglary after allegedly taking two laptops from a residence on the Gold Coast. The charges were withdrawn after mediation with complainants.
In August 2011, Cooper was accused of deliberately kneeing Richie McCaw in the face at the 2011 Tri Nations test, but at the subsequent SANZAR judicial hearing in Brisbane the charge was dismissed.
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". He also said he would not play for the Wallabies under those conditions. As a result, Cooper was fined a record $60,000 (of which $20,000 was a 2-year suspended sentence) and given a suspended three-match Wallabies ban. It was thought that the incident would prompt Cooper to abandon Australian rugby. However, he recommitted to the Reds and ARU.
In May 2016, Cooper stated that he had been dumped from the Australian Sevens team for the Olympic Games because he did not hold Australian citizenship. It was revealed that he had been travelling on a New Zealand passport while playing internationally for Australia.Representative Honours: Australian Schoolboys Squad, (05, 06), Australian Under-19 Squad. Tied 2nd highest all-time caps.
Queensland Debut: Queensland Reds vs Japan at Tokyo National Stadium Tokyo, 10 November 2006
International Debut: Australia vs Italy at Padova, Italy, Saturday, 8 November 2008.
Awards: 2010 Investec Bank Super 14 Australian player of the series.
Australia's Greatest Athlete (season 3): series winner
Championships: Super Rugby: 2011
Tri-Nations Champions: 2011