The Brazillian was officially unveiled in Spain on Friday following the conclusion of a deal reportedly worth in excess of £50million.
The Premier League side said in a statement: "Leeds United can confirm Raphinha has today completed a transfer to FC Barcelona for an undisclosed fee."
The tricky forward was reportedly wanted by both Chelsea and Arsenal, but will now play his football in LaLiga next season.
Despite their well-documented cash-flow problems, Barcelona indicated their ability to finance a deal for the 25-year-old which could rise to a reported £54.7m including add-ons.
Raphinha joined Leeds from Rennes on deadline day in October 2020 for a reported fee of £17m and went to make 67 appearances for the club, scoring 17 goals.
And the club's farewell message to the South American was a touching one after he played a key part in keeping them in the top flight last season.
They added in their statement: "We would like to place on record our sincere gratitude to Raphinha for his effort and contribution whilst at the football club.
"He showed unquestionable commitment and professionalism until the very end of his time at Elland Road and his celebrations at the Brentford Community Stadium will live long in the memory.
"Everyone at Leeds United would like to wish Raphinha the very best for the future and hope he enjoys great success at the Nou Camp and throughout his career."
Leeds have signed six new players since retaining Premier League status on the final day last season, while Raphinha's departure follows the sale of Kalvin Phillips to Manchester City for £45m.