Ferdinand shocked guests, and staff, when he turned up at Shoreham café La Patisserie.
The retired football legend, who played as a central defender for a number of clubs including Manchester United, Leeds United and West Ham, took photos with those he met in the West Sussex seaside town.
Cafe manager Hélène Berthillot: "We were very privileged to be here when he came.
"He stayed an hour or so and was really relaxed about it.
"It was lovely to see people stopping by to have a chat and take pictures.
"We saw some little boys with their jaws dropping when they realised who it was. It was really cute."
Antoine Berthillot, who took Ferdinand's order, said: "He came in and ordered a double machiato and a bottle of water.
"We even asked for a photo and he was very nice about it.
"He stayed for roughly an hour outside and wasn't bothered too much by people walking by. He even ended up saying he would be back."
Ali Mahmood, who made the now-football pundit's coffee, said: "Machiato with one sugar was his drink. Very nice and humble guy."