Ukrainian international defender Dmytro Chygrynskiy completed his ?25 million ($35.77 million) move from Shakhtar Donetsk to Barcelona on Monday, according to CNN.
The 22-year-old successfully came through a medical at the Nou Camp before signing a five-year deal with the reigning Spanish and European champions.
Chygrynskiy has a ?100 million ($143.07 million) buyout clause in his new contract.
"I feel lucky to sign for Barca. I`m hoping to improve and form a part of this great team, he told the official Barcelona Web site www.fcbarcelona.com.
Chygrynskiy played his final game for UEFA Cup winners Shakhtar in last Friday`s European Super Cup against Barcelona in Monte Carlo, a condition of the deal reached between the two clubs.
Barcelona won the match 1-0 to add to their victory in the Spanish Super Cup and complete a successful pre-season.
The Catalan giants begin their Primera Liga campaign later on Monday with a home match against Sporting Gijon.
Chygrynskiy is their fourth signing of the summer, following Inter Milan striker Zlatan Ibrahimovic, Maxwell and Kerrison, who has been loaned out to Benfica for the season.
He has played 19 times for Ukraine, establishing himself as a regular for his country.
He joins a club who completed a historic treble last season under new coach Pep Guardiola, but face a renewed challenge from arch Spanish rivals Real Madrid, who have spent heavily in the transfer window on the likes of Cristiano Ronaldo and Kaka.
Guardiola has allowed Eidur Gudjohnsen to move to French club Monaco, with the 30-year-old Iceland striker signing a two-year deal after failing to earn a regular first-team place in his three seasons at the Nou Camp.
The fee for Gudjohnsen could rise to $2.8 million dependent on performance clauses.
Real continued their spending on Monday with the signing of 19-year-old striker Jose Luis Mato from Celta Vigo.
Mato, who is known as Joselu, will be loaned back to the second-flight Galician side for the rest of the season.