Organisers announced Woody Allen’s "Café Society", featuring Stewart, will open the 69th edition of the festival which will run from May 11 to 22.
The American actress also stars in French director Olivier Assayas' "Personal Shopper", a film that will be vying for the Palme d'Or.
"She’s in some ways the Queen of Cannes," festival director Thierry Fremaux said during a ceremony in a Champs Elysees cinema as he unveiled the list of movies that will be screened.
Fremaux and his team watched 1,869 films before shortlisting 49, 20 of them included in the main competition, whose jury will be presided by Mad Max director George Miller.
Two films expected to gain a lot of attention despite being screened 'out of competition' will be Steven Spielberg's "The BFG", based on the novel by Roald Dahl, and the American thriller "Money Monster" which is directed by Jodie Foster and stars George Clooney and Julia Roberts.
While Roberts has never previously featured in a Cannes film, Foster will be at the festival for the first time as a director.