[4] On 1 July 2008, he was also given a four-month suspended sentence after admitting assault occasioning actual bodily harm on former teammate Ousmane Dabo during a training-ground dispute on 1 May 2007.

[6] Barton has been charged with violent conduct three times by The Football Association: for the assault on Dabo,[7] for punching Morten Gamst Pedersen in the stomach,[8] and for attacking three players in the final game of the 2011–12 season where he got sent off against Manchester City.

[citation needed] Barton would have made his debut for the City first team in November 2002 against Middlesbrough, had he not lost his shirt after leaving it on the substitutes bench at half-time.

[citation needed] After impressing in his first season at City, Barton was offered a new one-year contract at the club by manager Kevin Keegan, which he signed in April 2003.

[22] He featured in the first team more regularly during the 2003–04 season and, following a second Premiership goal, was rewarded with a call-up to the England U21 squad for their 2004 European Championship qualifiers against Macedonia and Portugal.

[34] In the autumn of 2005, Barton began a seven-day programme of behavioural management at the Sporting Chance Clinic, a charity set up to help troubled sportsmen and women.

[41] However, on 30 September 2006, television cameras captured Barton exposing his backside to Everton fans, following City's injury-time equaliser in a match at Goodison Park.

[43][44] Merseyside Police looked into the incident, but announced in October that no further action would be taken,[45] although Barton was fined £2,000 for bringing the game into disrepute and warned about his future conduct by The Football Association.

[33] The contract negotiations had become protracted after Manchester City refused to pay Barton a fee of £300,000 to which he was reported to be entitled if he left the club without submitting a request for transfer.

[65] After serving his ban, he played 75 minutes in a reserve match and said he wanted to transform his image to become a role model,[82][83] before he returned to action in the Tyne–Wear derby on 25 October.

[93] The club suspension was widely reportedly to have resulted not directly from the red card, but from a dressing room confrontation with Shearer and assistant manager Iain Dowie following the match.

[100] Barton courted controversy once again during Newcastle's 3–1 win over Liverpool on 11 December 2010, when he appeared to direct homophobic remarks and a lewd gesture at Fernando Torres.

[123] On 13 May, on the final day of the season, with QPR requiring at least a draw in their match away at Manchester City or for Bolton Wanderers to not win in order to guarantee Premier League safety, Barton was sent off in the 55th minute for violent misconduct after elbowing Carlos Tevez in the face.

[124][125] Barton had to be dragged from the pitch by former teammate Micah Richards[126] as he rowed with Manchester City players and staff and attempted to square-off with striker Mario Balotelli.

QPR also began an internal investigation into his behaviour,[129] amid speculation that he would be stripped of the captaincy, fined and possibly either sold, released on a free transfer or have his contract terminated for gross misconduct.

[136] Towards the end of the season, chairman Tony Fernandes identified the loss of Barton as a factor in the club's poor performance and relegation from the Premier League, saying: "We missed Joey.

[141] Barton told ESPN that he would not return to Queens Park Rangers after the loan spell, and he also said that he only joined the club for money because his partner was expecting a child.

[143] In his third league appearance on 2 December, Barton provided the assists for both Souleymane Diawara's and André Ayew's goals as Marseille defeated Brest 2–1 to remain two points behind leaders Lyon.

[150] He was sent off in QPR's 1–0 home defeat to Leicester City on 21 December 2013, receiving two yellow cards in quick succession for fouling and then throwing the ball in dissent at Gary Taylor-Fletcher.

[151] He started for QPR as they beat Derby County 1–0 in the 2014 Championship play-off final at Wembley Stadium on 24 May, a result that saw the club promoted back to the Premier League at the first attempt.

[152] On 21 February 2015, Barton received the ninth red card of his career in the 32nd minute of a match against Hull City after swinging at Tom Huddlestone's groin following a foul by Darnell Furlong.

[153] Chris Ramsey suggested that Barton, who would miss the club's next three home matches as a result, would return to anger management therapy following the incident.

[185] On 13 April 2019, following a 4–2 away defeat to Barnsley, South Yorkshire Police launched an investigation after Barton allegedly assaulted opposition manager Daniel Stendel in the tunnel.

[194] Barton was unable to reverse his side's slip down the table and on 24 April, they were officially relegated following a 1–0 defeat at Portsmouth that saw the club sitting bottom of the league, nine points off of safety with just two matches remaining.

[202] Barton was named League Two Manager of the Month for March 2022 at the second time of asking after leading his side to five wins from seven matches whilst conceding just three goals and pushing for a promotion place.

Commenting on figures from Friedrich Nietzsche and George Orwell to Isambard Kingdom Brunel and Morrissey, his eclectic tweets have resulted in him being described by the BBC as "a philosophical sportsman to rival Eric Cantona in his heyday".

[242] On 13 April 2019, South Yorkshire Police launched an investigation after Barton was alleged to have assaulted opposition manager Daniel Stendel in the Oakwell tunnel following a game between Fleetwood Town and Barnsley.

[243] In March 2022, a court heard that Barton was accused of kicking his wife in the head and grabbing her throat while drunk, the case being adjourned to 23 June due to a late arrival of emails.

[250] However, Vine stated that the £75,000+costs was an offer made at an earlier stage, and subsequently Barton went on to make further defamatory statements, and that the legal process continues in respect of these.

[254] In December 2024, Barton was additionally charged with malicious communication relating to social media posts referring to Jeremy Vine and Lucy Ward.