The Inception actress, 35, gave onlookers the first glimpse of her baby boy while departing from LAX Airport Tuesday. The Oscar winner welcomed son Marcel in May with her French actor-director beau Guillaume Canet.
Cotillard and Canet, 38, first starred together in 2003's Love Me If You Dare and began dating in 2007. The couple most recently collaborated for the movie Little White Lies, which Canet directed.
Cotillard's next film, the ensemble thriller Contagion, co-stars Matt Damon, Gwyneth Paltrow, Jude Law, Kate Winslet, Laurence Fishburne and Sanaa Lathan. It arrives in theaters September 9.