Barcelona are paying a base fee of €22million, with a further €7million available in add-ons. Dortmund have also secured a substantial 35 percent sell-on clause as part of the agreement. Adeyemi has signed a contract with the Catalan club running until 2031.
Borussia Dortmund originally signed Adeyemi from RB Salzburg in the summer of 2022 for €30million. In 146 appearances for the club, the left-footed forward was directly involved in 61 goals, scoring 36 and providing 25 assists. He won four caps for Germany between 2021 and 2022 under his new Barcelona head coach, Hansi Flick.
Dortmund's sporting director Lars Ricken explained the thinking behind sanctioning the sale.
"Karim was an important part of Borussia Dortmund over the past four years. In 2024 we reached the Champions League final with him. And yet this summer we agreed that both Karim and we want to head in a different direction in the future. When Karim came to us with the wish to move to FC Barcelona, we agreed to it after weighing up all of Borussia Dortmund's interests."
Adeyemi's move to Barcelona is widely seen as being driven above all by his relationship with compatriot and head coach Flick.
"He is the main reason," the forward said at his unveiling press conference. "He told me what the club needs, and I am here to prove it."
He expanded on the conversation that persuaded him to push for the move.
"We had a long conversation. He asked me if I was ready, and I said that I would give everything. For me, this is a big step. It is a completely different club to the others in the world."
Adeyemi leaves Dortmund having been a key part of the side that reached the 2024 Champions League final, and joins a Barcelona squad already being reshaped by Flick this summer as the club looks to build on last season's success. His pace and directness are expected to offer a different profile in attack compared to the options already available to the head coach.
The transfer represents a notable discount on the fee Dortmund originally paid to bring Adeyemi to the Bundesliga, reflecting the fact he had entered the final year of his contract at the Westfalenstadion without extending, which limited the club's negotiating position. The 35 percent sell-on clause secured by Dortmund does, however, give the Bundesliga club a meaningful stake in any future increase in his value, should Barcelona choose to sell him on again down the line.
For Barcelona, the deal continues a summer in which the club has moved to add depth and versatility across the forward line, with Adeyemi capable of playing anywhere across the front three.
His reunion with Flick, who gave him his senior Germany debut, is seen internally as a significant factor in smoothing his integration into the squad, with the head coach having a clear idea of how to get the best out of the pacy forward's game.