Kounde, 23, will join for a fee of €55 million and sign a contract at Camp Nou until 2027, sources have told ESPN. Once Kounde passes a medical and signs his contract, he will become Barca's sixth signing of a busy summer following the arrivals of Pablo Torre, Franck Kessie, Andreas Christensen, Raphinha and Robert Lewandowski.
"I am very proud and grateful for this opportunity," Kounde said. "I am excited because I am joining a great club with a great team. I am looking forward to getting going with the team and giving my best. Sevilla are a great club as well, of course, but Barca represent the next step in my career at every level. I want to compete in all competitions and try to win as much as possible, that is why I am here.
"The coach, Xavi, is one of the big reasons why I am here, too. I spoke with him several times. The way he spoke was captivating. We had some good conversations and we see football in the same way. Now it's a question of coming into the team, settling in and giving my all to have as many minutes as possible and an important role in the side."
Premier League side Chelsea were also interested in Kounde and held talks with Sevilla, but sources told ESPN the player's preference to move to Barca proved decisive in the end.
Barca coach Xavi Hernandez was especially insistent on the signing, sources added, and had maintained regular contact with Kounde in the weeks leading up to the transfer.
Chelsea also competed with Barca for Raphinha and Lewandowski, with both players opting to move to the LaLiga side, who remain interested in signing right-back Cesar Azpilicueta from the English team.
The Blaugrana are now well-covered at centre-back, with Kounde and Christensen joining to provide competition for Ronald Araujo, Gerard Pique and Eric Garcia. Kounde and Araujo can also play at right-back.
Kounde, who has 11 caps for France, signs for Barca after three years in Spain with Sevilla, during which time he has made 133 appearances and scored nine goals.
He joined Sevilla in 2019 from Bordeaux for around €25m and the French club, recently relegated to Ligue 2, are due a percentage of the fee.