A statement on Galatasaray's website read: "The transfer of Wesley Sneijder from Inter Milan has been agreed.
"The conditions of the deal will be made public and the player will sign the contract after health checks [his medical]."
The 28-year-old will complete his medical on Monday.
"It will be amazing and the atmosphere will be nice, I can't wait to go there and play my first game," Sneijder told the club's official website.
"I will make the Galatasaray fans very proud and very happy. I'm looking forward to meeting them and making a good life together."