Reports suggest the Turkish giants are paying €7.5m for Inter Milan's 28-year-old playmaker, who will be on a three-and-a-half year contract at €5m per season.
A statement on the club's website confirmed the deal after weeks of drawn-out rumours, with Sneijder supposedly holding out in case of a more attractive offer.
But, with nothing forthcoming, Sneijder -- who has been excluded from the last few Inter games after contract negotiations broke down -- has now joined the club currently sitting a couple of points top of the Turkish Süper Lig.
"The club have reached agreements with Inter and Wesley Sneijder," the statement read. "The conditions of the agreement will be announced when the player has passed health checks. Additionally, we will announce his time of arrival."
The Dutch international. has made just five appearances in total this season after four seasons at the San Siro, scoring 13 goals in 76 total appearances.