Haenel, an award-winning actress in movies such as Portrait of a Lady On Fire, has accused Ruggia of repeatedly touching her inappropriately after they met working on the film The Devils in 2001 when she was 12 and he was 36.
She first publicly accused him in 2019 of exercising undue control over her, isolating her from her family and crew members and forcing her and co-star Vincent Rottiers to film gruelling scenes they were uncomfortable with.
Ruggia denies the allegations, which carry a maximum sentence of 10 years in jail, and a 150,000 euro ($A246,500) fine.
His lawyer Fanny Colin declined to comment.
Haenel has become the first famous face of the #MeToo movement in France, where it has received a much more tepid reaction than in the US.
She recently retired from the film industry, citing complacency over alleged sexual predators still working in the business.
Haenel's lawyer did not respond to a request for comment.
Ruggia is not the first man in French cinema to face charges over his behaviour on set.
Gerard Depardieu, one of France's leading actors, is due to go on trial in 2025 over accusations he sexually assaulted two women on a film set in 2021.
Haenel accuses Ruggia of abusing her from the age of 12 to 15, during and after filming The Devils, which tells the story of two abandoned siblings searching for their home.
She told investigators she often went to Ruggia's house, where he would touch her between her legs and caress her chest.
She said his actions affected her school work and provoked suicidal thoughts.
"Christophe told me that he was in love with me and that the age difference was a curse for him and that unfortunately, I was an adult in a child's body," she told police.
The trial is expected to last two days.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
