The former England international showed no emotion as he was sentenced at Bradford Crown Court today.
Johnson, who played for Premier League clubs Sunderland and Manchester City, was found guilty of sexual activity with the teenager following an incident in his Range Rover in County Durham in 2015.
The 28-year-old admitted another charge of sexual activity with a child and grooming the girl.
Johnson stood with his hands behind his back as Judge Jonathan Rose passed the sentence.