English Soccer Star: Guilty of Sexual Activity w/ 15-Year-Old

English soccer star Adam Johnson -- a former member of the English national team -- was convicted of sexual activity with a 15-year-old girl and will likely go to prison.

The 28-year-old -- who played for Sunderland in the English Premier League -- was accused of hooking up with the girl in his Range Rover back in January 2015.

The girl told cops Johnson put his hands down her pants and she performed oral sex on him. Johnson was cleared of the oral sex charge ... but found guilty of digitally penetrating the child.

During the hearing, the judge told Johnson a prison sentence was "almost inevitable."