The 21-year-old, who left the Magpies by mutual consent a fortnight ago, was arrested after police received reports of a fight between a couple in the city centre on Wednesday evening.
The London-born former England Under-19 player was held after an alleged assault in the car park of The Gate entertainment complex.
Earlier, a Northumbria Police spokesman said: "At 7.09pm yesterday evening police received a report of a fight in the car park area at The Gate, Newcastle.
"A 21-year-old has been arrested on suspicion of assault and he is currently in custody helping police with inquiries."
A force spokesman said later that Ranger will appear before Newcastle Magistrates' Court on Friday.