Saint-Étienne Having been in the youth system since 2015, Fofana signed his first professional contract with
Saint-Étienne on 15 May 2018. He made his debut for the club in a 3–0 league win over
Nice on 18 May 2019.
Leicester City Fofana joined English
Premier League club
Leicester City on 2 October 2020, signing a five-year contract. The transfer fee paid to Saint-Étienne was reported as up to £36.5 million. On 15 May 2021, he played in the
2021 FA Cup Final, which Leicester won 1–0 for his first career honour in England. He and teammate
Hamza Choudhury both celebrated draped in the
flag of Palestine, during the
2021 Israel–Palestine crisis. On 21 May 2021, Fofana won Leicester City's Young Player of the Season award after being voted by the club's supporters. On 4 August 2021, during a pre-season friendly against
Villarreal, Fofana suffered a broken leg following a challenge by
Fer Niño. On 17 March 2022, Fofana played his first match since his injury, scoring in a 2–1 defeat to
Stade Rennais in the
UEFA Europa Conference League which secured Leicester's progress to the next round on a 3–2
aggregate score.
Chelsea On 31 August 2022, Fofana joined Premier League club
Chelsea on a seven-year contract for a reported initial fee of £70 million, plus £5 million in add-ons. After signing for Chelsea, Fofana criticised his former club Leicester City, accusing them of issuing "false and misleading comments" during his protracted transfer. On 3 September, he made his debut for the club in a 2–1 win at home against
West Ham United in the Premier League. He scored his first goal for Chelsea on 5 October in a
Champions League 3–0 victory against
AC Milan at
Stamford Bridge, but suffered a major
knee injury after 38 minutes, forcing him to be substituted off, and was ruled out until February 2023. Fofana returned from injury on 18 February 2023, in a 1–0 home defeat against
Southampton. He scored his first ever Premier League goal against
Leeds United on 4 March, in a 1–0 home victory. On 18 July 2023, Chelsea revealed that Fofana had suffered an
anterior cruciate ligament injury (ACL) and had undergone a surgery. In late November 2023, it was announced that Fofana had been cleared to resume training following his recovery from the ACL injury. However, he was unable to feature in any match during the 2023–24 season due to his injury. On 21 February 2026, Fofana was shown a second yellow card after the foul he made on
James Ward-Prowse in the 1–1 home draw against
Burnley. This made him the sixth Chelsea Premier League player to be sent off in this season.{{cite news |first=Nizaar |last=Kinsella ==International career==