The 30-year-old playmaker returns to his native Turkey having failed to make a single appearance under Ernesto Valverde this season.
It is that lack of game time which has forced him to move on as he seeks more regular first-team football.
Barca have acknowledged as much and allowed Arda to depart on a two-and-a-half-year loan agreement.
A statement on the club’s official website read: “Arda Turan has played a total of 55 games for Barca, scoring 15 goals in his two-and-a- half years as a Blaugrana.
“In that time he has won 6 trophies: 1 league championship, 2 Copa del Rey, 1 Spanish Super Cup, 1 Club World Cup and 1 European Super Cup.
“As such the Turk leaves after completing a clean sweep of domestic trophies.”
Arda joined Barca from Atletico Madrid in the summer of 2015.
He was acquired by those at Camp Nou having shone for their La Liga rivals during a period of considerable success in the Spanish capital.
He was, however, to face fierce competition for places in Catalunya and was unable to nail down a regular role throughout his time with Barca – having initially been forced to wait for his debut as a result joining during a transfer embargo.