Olivier Le Sage is a guest character on 90210, portrayed by William Abadie.
Olivier is mention several times before his actual appearance on the show in the episode Meet the Parent. He is the estranged husband of Jen Clark. When Jen first arrives in town after a long absence, she is separated from Olivier. However, after she blows into town and disrupts everyone's lives, she leaves town and goes back to France, where Olivier and Jen reconcile.
Olivier returns with Jen and unknowingly meets Jen's ex, Ryan Matthews. After arranging a dinner with Jen and her sister, Naomi, he is made aware by Naomi of Jen's past actions, at which point Oliver voices his disgust with Jen.
After the dinner incident, however, Jen gets a settlement and reveals her plan all along was to get some of Olivier's money in their divorce settlement.