Szczesny, who is 35 years old, has been more involved in the team than expected. He played in 30 games and helped the team win a domestic treble, conceding 36 goals and keeping 14 clean sheets.
His contract was set to expire this summer, but after discussing the terms with the club, Szczesny has agreed to extend his deal until 2027.
With the signing of Joan Garcia from Espanyol, Barcelona now has a strong lineup of goalkeepers.