The Argentine wizard played 778 times for Barcelona's first team, scoring 672 times.
Messi is, of course, in Barca's best XI ever. But who else joins him?
OneFootball gave themselves the tough task of naming Barca's best XI in history. View who they selected below...
GK: Andoni Zubizarreta
Zubizarreta spent eight seasons at Barcelona from 1986-1994.
He made 410 appearances in that spell and helped Barca to four La Liga titles.
The Spaniard also holds the record for the most clean sheets in La Liga history (235).
RB: Dani Alves
Alves is considered by many to be the best right-back of all-time.
There was no weakness to his game - he was tenacious in defence and brilliant going forward.
Now 38, Alves recently re-signed for Barca and is hoping to bring former glories back to the club.
CB: Carles Puyol
Puyol wasn't the biggest defender, nor was he the quickest, but he was without doubt the most dedicated.
The defender gave everything whenever he stepped out on the pitch and demanded the same from his teammates.
He made 682 appearances for Barca and helped them to 18 major honours in that time.
CB: Ronald Koeman
Koeman's record in front of goal during his six-year spell at Barca was just ridiculous.
He scored 88 times in 264 games, an incredible tally for a defender. His most important strike came in the 1992 European Cup final, where he scored the only goal in a 1-0 victory over Sampdoria.
LB: Sigfrid Gràcia
Gracia was a Barcelona player from 1949-1966.
During his spell he played 536 times, scored 23 goals, and helped Barcelona to three league titles.
DM: Sergio Busquets
Busquets was and still is a wonderful player.
Gifted with world-class technical ability, insane composure and an elite footballing brain, Busquets is always in the right place and it's almost impossible to get the ball off of him.
Now 33, Busquets continues to play at the highest level.
Xavi was a wonderful technician. He dictated the tempo whenever he pulled on a Barcelona shirt.
In total, he played 767 times for the club and scored 85 times.
AM: Johan Cruyff
Cruyff is considered to be one of the greatest players ever. He played 180 times for Barca and scored 60 times.
Ronaldinho's time at the top wasn't the longest. But when he was at his best he was virtually unplayable.
The Brazilian had every trick in the book and was capable of making anyone in the world look like an amateur.
He scored 94 times in 207 games for the club and helped Barca win five trophies.
RW: Lionel Messi
Of course Messi makes Barcelona's best XI. He's arguably the sport's best ever player, after all...
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ST: László Kubala
Kubala is the definition of a club legend.
The Budapest-born striker scored 194 times for the club from 1950-1961.
He was so good that, per Goal, he was voted Barcelona's best ever player in a fan conducted in 1999.
What a side. Players that will go down in Barcelona's history but didn't quite make the side include Hristo Stoichkov, Andres Iniesta, Gerard Pique, Luis Suarez, Neymar, Rivaldo and Pep Guardiola.