The Manchester United ace has been tipped to leave Old Trafford this summer.
The 29-year-old has less than year left on his current contract and the imminent arrival of Nemanja Matic is set to force the former Everton star out.
And according to the Guardian, Fellaini could leave United within 48 hours.
They say the Belgium international has agreed a four-year contract with Galatasaray.
Fellaini will earn £3.6m-per-year, making him their highest paid player.
The Guardian add that the Turkish club’s president Dursun Ozbek is due in Manchester tomorrow or Tuesday to complete the deal.
Galatasaray sporting director Cenk Ergun claimed this week he is a huge fan of Fellaini.
“Fellaini will leave Manchester United and he is now in our radar,” Ergun told Ajansspor.
“There will be surprises (in the transfer window), we are in talks with Fellaini.
“We have made an approach, we are close and if we get Fellaini we will end our pursuit of (Villarreal’s Alfred) N’Diaye.
“We need a player like Fellaini who can move around in midfield.”
