The Spanish playmaker scored in the Champions League final last season as she led the dominant Catalan giants to a sensational quadruple.
"The best player in the world is thus staying at a winning club," wrote Barcelona in a statement.
Bonmati has 96 goals for Barcelona in 275 games and is the joint record Champions League goalscorer with 22, tied with team-mate and two-time Ballon d'Or winner Alexia Putellas.
Also a World Cup winner with Spain in 2023, Bonmati came through the Barcelona youth academy after joining the club in 2011.
