Kessie built up a reputation as one of the top midfielders in Italy over the last three years, taking his game to the next level after a permanent move to Milan from Atalanta in 2019.
Speculation over the 25-year-old's future had been raging as he approached the final few months of his contract at San Siro, and Barca have now won the race for his signature. Kessie completed a medical before putting pen to paper on a four-year deal at Camp Nou, and will now join up with the rest of the squad for pre-season.
Barca have reportedly handed the Ivory Coast international a €6.5 million per year wage packet that could rise based on performance-based add-ons. Barcelona have confirmed that Kessie's contract includes a lofty release clause.
Any potential suitors will have to pay €500m to prise the midfielder away from the Blaugrana before his deal expires in 2026. Kessie scored 37 goals and provided 16 assists in 223 appearances for Milan, including those he earned during an initial two-year loan spell at San Siro.
The midfielder was named in the Serie A team of the Year for 2020-21, and left the club on a high by helping them lift their first Scudetto in 11 years. Barca have been able to register Kessie in the wake of agreeing the sale of 10 per cent of their La Liga TV rights to global investment firm Sixth Street Partners.
That deal will end up being worth a total of €267 million (£229m/$277m) to the Blaugrana, who have been working to balance their books after posting record-breaking debts in 2021.
Kessie is set to be joined at Camp Nou by another free agent in the form of Andreas Christensen, while Barca have also freed up funds to chase down primary targets such as Bayern Munich star Robert Lewandowski and Leeds winger Raphinha.