2018–19 FC Barcelona season

The 2018–19 season was Futbol Club Barcelona's 119th season in existence and the club's 88th consecutive season in the top flight of Spanish football. Barcelona was involved in four competitions after winning the double of La Liga and the Copa del Rey in the previous season.

Contrary to the expectations and primarily due to stellar Lionel Messi performances, Barcelona were in the running for a third continental treble, until 7 May 2019, when they infamously lost 4–0 to eventual winners Liverpool in the second leg of the Champions League semi-finals, having been up 3–0 after the first game. The league title was secured earlier on 27 April and Barça advanced to its sixth consecutive Copa del Rey final on 27 February . The loss at Anfield derailed the team and they went on to lose the Copa del Rey final as well, to Valencia. Barça's league title was its eighth in eleven seasons; their next league title would be won in 2022–23. Head coach Ernesto Valverde was sacked midway through the next season.

The season was the first since 2001–02 season without former captain Andrés Iniesta, who departed to join Vissel Kobe.