Jodie Foster does not have an accent when she speaks French, at least not a foreign sounding one. Her speech is perfectly natural.
You didn’t ask, but Kristin Scott Thomas’ French is also indistinguishable from a native’s. She has played French characters in French movies.
Also, Steven Segal speaks Japanese. His pronunciation is not bad, though he wouldn’t be mistaken for a native speaker. I heard him do a long interview on television, and like many people who have learned Japanese outside a classroom, he has some difficulty breaking out of informal speech, and there are some wholes in his vocabulary, but overall he’s quite listenable. That is, he would be, if he had something worthwhile to say.