The young 35-year-old woman and her boyfriend, actor and director Guillaume Canet, 37, have been living together since 2007.
The couple starred together on screen in Little White Lies, which Canet directed.
Marion Cotillard’s international career took off in 2008 when she won the Oscar for Best Actress for her portrayal of Edith Piaf in “La vie en rose”.
Although the actress was recently seen wearing a diamond solitaire, they are not engaged.
“They haven’t disclosed any plans concerning marriage,” a source says.