Cooper Cronk is an Australian former professional rugby league footballer who played in the 2000s and 2010s. An Australian international and Queensland State of Origin representative halfback, he played most of his club career for the Melbourne Storm, though finished his career with the Sydney Roosters, both in the National Rugby League.

During his sixteen-year career, Cronk won four NRL Premierships (in 2012 and 2017 with Melbourne, and 2018 and 2019 with Sydney) from nine NRL Grand Final appearances. He won the Dally M Medal as the NRL's player of the year in 2013 and 2016, the Clive Churchill Medal as best player in the 2012 NRL Grand Final, the Golden Boot Award as international player of the year in 2016, and the NRL's Dally M Halfback of the Year on five occasions.

Cooper Cronk was born in Brisbane, Queensland, Australia. Cronk played his junior rugby league with the Souths Acacia Ridge club. He attended St. Laurence's College, South Brisbane from 1994 to 2000, where he was in the school's 1st XV rugby union side for a number of years. He was selected to play in the Australian Schoolboys squad along with former Wallaby captain Rocky Elsom. In 2001, Cronk was selected to play rugby league for Queensland and Australian Schoolboys teams. He was then selected to play in the Queensland Cup's Norths Devils team. He quickly established himself in that competition and trained with the Storm Squad in 2003. He scored 37 tries for the Norths Devils in the Queensland Cup.

Cronk made his debut for the Melbourne Storm in 2004, starting as a utility back coming off the bench and playing at five-eighth, hooker and lock. In the 2006 NRL season, Cronk won the Dally M Halfback of the Year award. He also played at half-back for Melbourne in the 2006 NRL Grand Final loss to Brisbane.

When Cameron Smith was sidelined by a NRL Judiciary suspension during Melbourne's finals campaign of the 2008 NRL season, Cronk stood in as captain and captained the Storm in the 2008 NRL Grand Final defeat by Manly Sea Eagles. He played in the 2009 NRL Grand Final against the Parramatta Eels, setting up 2 tries. This title was later stripped due to salary cap breaches. Cronk was named as part of the Four Nations team and played for Australia in 2009 Four Nations Tournament in Australia against France as a utility.

Cronk played off the bench as a utility for Queensland in the 2010 State of Origin Series, playing in all three games. In Game II, he scored his first Origin try. Cronk played in the 2011 State of Origin Series. In Game I, he set up a try for Jharal Yow Yeh in the second half and in Game III, he set up Greg Inglis as well.

In March 2012 Cooper agreed to a further four years with the Melbourne Storm. At the 2012 Dally M Awards Cronk was named the NRL's halfback of the year.[10] In the 2012 NRL Grand Final victory over Canterbury-Bankstown, he won the Clive Churchill Medal for the man of the match award. Cronk kicked the game and series-winning field goal in the final minutes of the third State of Origin match in 2012. In February 2013, he won man of the match in Storm's 18–14 win over Leeds in the world club challenge.

Cronk broke his arm in the opening minutes of Game I of the 2014 State of Origin series on 28 May 2014. Written off for the series, he surprised the entire rugby league community by getting himself fit enough to take the field in Game III just six weeks later. Queensland lost the series after losing Games I and II, but in Game III on 9 July 2014 the Maroons routed New South Wales 32–8. In On 30 August 2014, Cronk played his 250th game for Melbourne Storm, a feat achieved by only three others players at the club.

2016 began with rumours linking him to rival NRL clubs in Sydney, most notably the St George Illawarra Dragons. However, he put that in the back of his head to lead Melbourne to a great start to the season. In June 2016, Cronk became only the fifth NRL player in history to record 200 wins (from 289 games) in a 29 to 20 win over the West Tigers. At the annual Rugby League Dally M awards in September 2016, Cooper Cronk was named the Dally M Player of the Year for a second time after winning his first in 2013. Cronk tied with North Queensland Cowboys prop Jason Taumalolo to win. This was further complemented on 22 December 2016, when Cooper Cronk won the 2016 Golden Boot Award for the Worlds best player.

In 2018 Cooper Cronk joined the Sydney Roosters. Where he played all 26 games, including playing with a broken scapula in the grand final victory over his former club the Melbourne Storm. He then became the first player to win consecutive premierships with two different clubs in the NRL era, having won the 2017 Grand Final with Melbourne and 2018 Grand Final with the Roosters starting at halfback in both games. Cooper also became the first player in the modern era to have three consecutive grand final appearances.

In September 2019, Cronk led the Sydney Roosters to a 14–6 win over his former club Melbourne Storm in the preliminary final. After the game, Cronk was full of praise for his former coach Craig Bellamy and the Storm. In October 2019, Cooper Cronk played his final game of Rugby League in the NRL for the Sydney Roosters in the 2019 NRL Grand Final. Prior to his last match, the only thing he had not managed to achieve is back-to-back titles with the same club. He did that, and set the record for three consecutive grand finals in the modern era, furthermore Cronk was the first player in the NRL era to have won three consecutive premierships.

Following his retirement from playing in 2019, Cronk has been part of the commentary team on Fox League, where he is seen as part of the broadcaster's on-air panels and analysis. In August 2024, the National Rugby League announced that Cronk was an inductee into the National Rugby League Hall of Fame. Cronk, who was ascribed Hall of Fame number 124, was amongst eleven male players in the 2024 Class.