Answer: FC Barcelona.
Some extra relevant information:
Lionel Messi, regarded as one of the greatest footballers of all time, has spent the majority of his illustrious career at FC Barcelona. Messi joined Barcelona’s youth academy, La Masia, at the age of 13 in 2003 and quickly progressed through the ranks. He made his first-team debut in 2004 at the age of 17, and since then, he has been an integral part of the club for nearly two decades.
Messi’s time at Barcelona has seen him establish numerous records and achieve unparalleled success. He has won numerous domestic and international titles with the club, including 10 La Liga titles and four UEFA Champions League titles. Additionally, Messi has clinched multiple individual honors, including six Ballon d’Or awards.
Despite citing his desire to leave Barcelona in 2020, Messi ultimately decided to stay with the club due to contractual complications. However, In August 2021, due to financial constraints and regulations imposed by La Liga, Barcelona reluctantly announced that Messi would be leaving the club. Messi subsequently joined Paris Saint-Germain (PSG), marking the end of his legendary tenure at Barcelona.
While Lionel Messi’s stint at PSG is yet to unfold, his time at FC Barcelona undoubtedly stands as the longest and most significant chapter in his remarkable footballing journey.