It will be Barca’s fifth signing of the pre-season after the arrivals of Robert Lewandowski from Bayern Munich and Raphinha from Leeds in addition to AC Milan’s Franck Kessie and Chelsea Danish central defender Andreas Christensen on free transfers.
An agreement between Chelsea and Sevilla appeared to be close last weekend, but Spanish media underlined the key role played by Barca coach Xavi Hernandez in the arrival of Kounde.
The 23-year-old is recovering from groin surgery following an operation last month but is expected to be available for the start of the new season.
Kounde joined Sevilla in 2019 from Bordeaux. He won the Europa League in his first season in Spain, and has played 11 times for France.
Barcelona have also prolonged the contract of French winger Ousmane Dembele until 2024.