The Fresh Prince of Bel Air star enjoyed lunch with 11 team members at Roger’s Kitchen in Camden Road.
Restaurant owner Roger Shakes, 48, said he was discreetly approached by Smith’s team when they made a large takeout order for £350.
The caller explained that a client would be visiting later in the week – but did not tell the owner who it would be.
In order to prepare, Mr Shakes claims he was asked to black out their windows and send photos of the layout to Mr Smith’s security team.
He said: “I was a bit hesitant, I thought maybe someone was trying to trick me.
“They asked me if we had anything to cover the windows because people might follow him in there. So we had to black out the windows.”
When the Oscar winner finally walked in, Mr Shakes says he was very surprised.
He added: “I thought maybe it was Beyonce or Jay Z because they were in town. We just had to wait and see who walked through the door.
“I was surprised – I hadn’t thought it could be him. I am a fan, I have been watching him since I was about ten years old on Fresh Prince of Bel Air.”
The restaurant owner says that the table of 12 ordered several dishes to share – and that their bill came to around £1,400.
He also said that Smith was very kind, and shook his hand to thank him for the food.
Mr Shakes said: “It was a good experience. He was very cool. They ordered a lot of food together to share. Jerk chicken, fish, curry, rice and peas. He was very relaxed and said he was very tired.”
Reporting by SWNS.