Touré made his debut for Ivory Coast in April 2000 against Rwanda. He played in all five games for the Ivory Coast as they finished runners up to the hosts in the African Cup of Nations in Egypt in January 2006.

Born in Bouaké, Touré joined Premier League team Arsenal from ASEC Mimosas on a long-term contract for a fee of £150,000 on 14 February 2002 after a short trial.

His status as a full international meant Touré was able to secure a British work permit. Touré did not make his debut for the first team until the next season, against Liverpool in the FA Community Shield in August 2002. Initially regarded as a utility player, he started his Arsenal career as a defensive midfielder as well as in right back. He scored his first Arsenal goal at Stamford Bridge in a 1–1 draw against Chelsea. Arsenal failed to retain the Premiership crown that season, but Touré made a big step in his career nonetheless, winning the FA Cup as an unused substitute in the final.

Touré scored his second European goal on 19 April 2006, the winner in the first leg of the Champions League semi-final against Villarreal CF. It was the final European goal scored at Highbury and the goal that effectively decided the tie (Arsenal won 1–0 on aggregate), to send Arsenal through to their first ever Champions League Final, in Paris, France.

Touré was handed the number 5 shirt for the 2006–07 season, which had been vacant since the departure of Martin Keown. In August 2006, Touré signed a new four-year deal with Arsenal.

He was named in the 23-man squad taken by coach Henri Michel to the 2006 FIFA World Cup and made his first appearance in a FIFA World Cup on 11 June 2006 in the Ivory Coast’s 2–1 loss to Argentina. He has scored three goals for the Ivory Coast to date, two of them headers against Guinea and Gabon one against Japan, a 20-yard shot from outside the penalty area that flew into the top corner of the goal.

Touré was the junior vice-captain in the 2006–07 season after former vice-captain Gilberto Silva and former captain Thierry Henry. He captained Arsenal for the first time on 9 January 2007 during a 6–3 victory over Liverpool in the League Cup. He also led the Gunners out for the final of this competition, having also captained them in the semi-final first leg against Tottenham Hotspur. He became the longest-serving member of the current Arsenal squad following the departures of Jérémie Aliadière, Thierry Henry and Freddie Ljungberg during the summer transfer window in 2007. He also captained Arsenal in a string of games early in the 2007–08 season after captain William Gallas was injured in the game against Blackburn Rovers. He scored a free kick in a match against Bolton Wanderers, where his shot was low and went under two Bolton players and beat Jussi Jääskeläinen. However, during the Africa Cup of Nations, he suffered an injury and looked a bit out of place when he returned and then injured himself again in the Champions League against A.C. Milan when he blocked Alexandre Pato’s shot with his leg and was carried off the pitch after treatment. Touré returned to the starting lineup against Middlesbrough on 15 March and scored the equalising goal for Arsenal in the final 10 minutes.

On 13 April 2009, Touré demanded a move away from Arsenal after a reputed bust-up with defensive partner Gallas. He reportedly handed in a transfer request which was later turned down by Arsenal chairman Peter Hill-Wood. However, Touré temporarily reversed his decision and committed to the Gunners at least until the summer.

After much transfer speculation, it was announced on 28 July 2009 that Manchester City had agreed a fee of £14 million for Touré. After he successfully passed a medical in Manchester on 29 July 2009, Touré signed a four-year contract with the club which had the option of extending it to five years. City, who had finished 10th the previous season, had made a number of high-profile signings in preparation for the 2009–10 season, and Touré hoped to help make City a top four team. He was appointed the club captain by Mark Hughes. He scored his first goal for Manchester City in a 2–1 League Cup win over Fulham on 23 September 2009. He scored his first league goal for City against Burnley on 7 November 2009. Manchester City finished the season in fifth position, losing out to Tottenham Hotspur by just three points. On 2 July 2010, Kolo Touré was joined by his brother Yaya at Manchester City following a transfer believed to be worth around £24 million.

At the beginning of the 2010–11 season, Roberto Mancini took away the captain’s armband from Touré and gave it to Carlos Tevez. However, he remained part of Mancini’s plans and was a first team regular in defence. He was sent off in Manchester City’s 2–1 defeat to Everton on 20 December 2010, helping to deny City the chance to top the Premier League table on Christmas. On 15 January 2011, Touré scored the first goal in a 4–3 win for the Citizens which sent them to the top of the league table.

On 3 March 2011, it was revealed that Touré had failed a drug test and had been suspended. The World Anti-Doping Agency imposed a 6-month suspension from football effective 2 March 2011.

On 28 May 2013, Liverpool announced that an agreement had been reached in principle to sign Touré on a free transfer from Manchester City. On 2 July he was unveiled as Liverpool’s first signing of the window and was handed the number 4 shirt. He signed a two-year contract. On 13 July 2013, he made his debut for Liverpool in a 4–0 win in a preseason friendly over Preston North End. He made his Premier League debut for Liverpool on 17 August 2013 in a 1–0 victory over Stoke City at Anfield. On 2 February 2014, in a match against West Bromwich Albion he made a costly mistake, passing the ball straight to Victor Anichebe, who scored an equaliser. On 12 February 2014, he scored an own-goal in a match against Fulham, which eventually Liverpool won thanks to a late penalty from skipper Steven Gerrard.

In December 2014, Touré announced his intention to retire from international football after the 2015 Africa Cup of Nations. He played his final game in the final of the tournament on 8 February 2015, where Ivory Coast beat Ghana 9–8 on penalties after the game ended 0–0. He took the seventh penalty for Ivory Coast, which he scored. On 15 February 2015, he confirmed his retirement from international duty.

He is the older brother of Ibrahim Touré and Qingdao Huanghai’s Yaya Touré. Ibrahim died of cancer in 2014, aged 28. They also have a sister, Belinda.

On 1 March 2015, he came on as an 83rd-minute substitute against Manchester City, marking the first time he and his brother Yaya, who started the match for City, faced each other in a competitive match.

Touré scored his first Liverpool goal on 14 February 2016, heading in Jordan Henderson’s corner kick to confirm a 6–0 win away to bottom side Aston Villa. It was his first goal in any match since January 2011, and he celebrated wildly.

On 24 July 2016, Touré reunited with former manager Brendan Rodgers when he joined Celtic on a one-year contract. He made his debut on 3 August 2016, coming on as a substitute in the second half of Celtic’s 2–1 win over FC Astana in a Champions League qualifier. He made 20 appearances as Celtic completed an unbeaten domestic season, winning a treble of League, Cup and League Cup. Touré was not offered a new playing contract at the end of the 2016/17 season.

In September 2017, Touré announced his retirement and took up a coaching role with Celtic.

On 9 August 2017, the Ivorian Football Federation appointed Touré as a new member of their coaching staff for the African Nations Championship and under-23 team. He joined Celtic’s coaching staff as a technical assistant in September 2017. In February 2019, Brendan Rodgers left Celtic for Leicester City, and Touré also joined Leicester as a first team coach.