According to the prosecution, both France internationals were aware that Zahia Dehar was a minor when they allegedly slept with her
France international Ribery is accused of knowing Zahia Dehar was a minor when, in 2009, he flew her to Munich before sleeping with her. He denies the charge.
Compatriot Benzema stands accused of paying for sex with Dehar in a Paris hotel when she was 16. He denies having had any sexual contact with her.
The maximum prison term for the offence is three years, but Ribery's lawyer, Carlo Alberto Brusa, says his client is "confident" that he will be found innocent.
"Mr Ribery is a mature person who has faced difficult times. He is as concerned as anyone who finds himself in the criminal justice system, but at the same time calm," he said.
"We are going in confident and we are going to fight."
Both Ribery and Benzema are currently expected to represent France at this summer's World Cup in Brazil.