Following an incident late on Wednesday evening, the 21-year-old - who recently had his contract with the Premier League club terminated - was held for questioning by police
Following reports of a fight between a man and a woman in Newcastle city centre on Wednesday evening, the 21-year-old was held by police.
Ranger is helping police with their inquiries following the incident, which is believed to have taken place in the car park of The Gate entertainment complex.
A statement from Northumbria Police 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."
The former England Under-21 international has a history with the police after being sentenced to a young offenders institute for 11 weeks at the age of 15 for his part in an attempted robbery before another alleged assault of a man in August 2011.
Ranger had his contract with Premier League side Newcastle terminated by mutual consent on March 1, ending a four-year association with the club.