Barcelona played their official home matches for the entire season at the Estadi Olímpic Lluís Companys due to the start of Espai Barça project to revamp the club's sporting facilities.
[7][8] In the knockout stage, they defeated Napoli 4–2 on aggregate in the round of 16,[9] with their Champions League journey ending in the quarter-finals where they were defeated by Paris Saint-Germain in part due to a Ronald Araújo red card in the second leg of tie, which tipped the scales in Paris' favor despite Barcelona's first leg win.
[10][11] Elsewhere, Barcelona finished as runners-up in the Supercopa de España,[12] and was eliminated in the quarter-finals of the Copa del Rey in extra-time by the eventual winners Athletic Bilbao.
[32] On 22 July, the club announced that their match against Juventus on the same date would be cancelled due to a viral gastroenteritis outbreak among a significant part of the Barcelona squad.
[34] On 29 July, Barcelona got their first win of the pre-season, after they defeated Real Madrid 3–0 in the El Clásico thanks to goals from Ousmane Dembélé, Fermín López and Ferran Torres.
[38] The goals were scored by Robert Lewandowski, Ferran Torres, Ansu Fati and Abde Ezzalzouli, while Frenkie de Jong was chosen as Player of the match.
[49][50] On the same day the club also announced that they had sold Abde Ezzalzouli to Real Betis for €7,500,000, and confirmed that they had loaned out three players until the end of the season: Clément Lenglet to Aston Villa,[51] Ansu Fati to Brighton & Hove Albion[52] and Eric García to Girona.
[54][55] Gavi made his 100th appearance for Barcelona, thus becoming the youngest Barça player ever to become a centenarian, reaching the figure at the age of 19 years and 27 days.
[73] Sergi Roberto and Lamine Yamal scored a goal each, and with his goal Lamine Yamal became the youngest La Liga goalscorer ever aged 16 years and 87 days, breaking the record held by Malaga's Fabrice Olinga, who scored against Celta Vigo in 2012 aged 16 years and 98 days.
[82] On 7 November, Barcelona suffered a narrow 1–0 defeat against Shakhtar Donetsk under controversial circumstances after three penalties for the team were denied by Video Assistant Referee (VAR), of which two were handballs inside the box which were not called and the third was a foul on João Félix inside the penalty area which was also not given even after VAR checked the incident.
[89] On 10 December, Barcelona suffered their second league defeat of the season, losing 4–2 to Girona, with Robert Lewandowski and İlkay Gündoğan scoring the only goals for the team.
[94] Barcelona got a hard-fought 3–2 victory over Almería in their last competitive match of the year on 20 December, thanks to a brace from Sergi Roberto and a goal from Raphinha.
[101] On 7 January, Barcelona defeated Barbastro 3–2 and advanced to the Copa del Rey round of 16 thanks to goals from López, Raphinha and Lewandowski.
[102] On 11 January, Barcelona advanced to the 2024 Supercopa de España final after they defeated Osasuna 2–0 in the semi-final thanks to goals from Lewandowski and Yamal.
[106][107] On 18 January, the team advanced to the Copa del Rey quarter-finals after they defeated Unionistas 3–1, with the goals coming from Torres, Koundé and Balde.
[127] Barcelona ended the month with a comfortable 4–0 win against Getafe on 24 February, with the goals coming from Raphinha, Félix, De Jong and Fermín.
[135] On 12 March, Barcelona advanced to the Champions League quarter-finals for the first time since the 2019–20 season after defeating Napoli 3–1 on the night and 4–2 on aggregate,[136] with the goals coming from Fermín, Cancelo and Lewandowski.
[138][139] On 17 March, Barcelona defeated Atlético Madrid 3–0 thanks to goals from Félix, Lewandowski and Fermín and climbed to second place in the league standings.
[144][10][145] Three days later, the team got a 1–0 away win over Cádiz thanks to a brilliant bicycle kick goal from Félix and an amazing defensive performance from Ter Stegen.
[146] On 16 April, Barcelona's Champions League journey ended after they suffered a 4–1 defeat in the second leg of the quarter-finals against Paris Saint-Germain (6–4 on aggregate).
Despite Barcelona's promising start thanks to a Raphinha goal, the pivotal moment of Araujo's red card in the 29th minute altered the trajectory of the match and ultimately swung the momentum decisively in PSG's favour.
Four minutes later, after being checked by the VAR, the result was deemed inconclusive because of the lack of the goal-line technology in La Liga and therefore the goal was not allowed.
[15][166] On 29 May, Barcelona announced that the German manager Hansi Flick would become the team's head coach starting next season with a contract until 30 June 2026.
[25][26] On 12 July, the club announced they would face Tottenham Hotspur on 8 August to dispute the Joan Gamper Trophy at the Estadi Olímpic Lluís Companys.
[193] On 22 July, the club announced that their match against Juventus on the same date would be cancelled due to a viral gastroenteritis outbreak among a significant part of the Barcelona squad.
[34] On 29 July, Barcelona got their first win of the pre-season, after they defeated Real Madrid 3–0 in the El Clásico thanks to goals from Ousmane Dembélé, Fermín López and Ferran Torres.
[38] The goals were scored by Robert Lewandowski, Ferran Torres, Ansu Fati and Abde Ezzalzouli, while Frenkie de Jong was chosen as Player of the match.
[12] Barcelona, as a last season's winner of one of the highest ranked leagues in Europe, entered in Pot 1 for the group stage draw, which was held on 31 August 2023.
[206] As a result of finishing top of the group, Barcelona were seeded for the round of 16 draw which took place on 18 December 2023, and would play the second leg at home.
They were drawn against Italian side Napoli, who finished second in Group C.[209] The draw for the remaining knockout rounds of the competition was held on 15 March 2024 in Nyon.