Chinese actor Chang Chen, French director Robert Guediguian, Burundian singer Khadja Nin and Russian director Andrey Zvyagintsev will also serve as the jury members.
"Blade Runner 2049" and "Arrival" director Villeneuve has had several films at the festival including "Sicario", while Stewart has appeared in Cannes selection including "Personal Shopper" and "Clouds of Sils Maria". We've started paying more attention to the gender ratio on our selection committees, for instance.
Blanchett, a two-time Oscar victor, is heading the jury that features five women, four men, seven nationalities and five continents.
Organisers had already announced earlier this year that the Australian-born actress Cate would head the jury.
This year's festival runs from May 8 to 19 at the French Riviera resort.
Director-writer-producer Ava DuVernay recently directed Disney's adaptation of A Wrinkle in Time and champions women and filmmakers of color with her collective ARRAY.
Seydoux, a French actor, rose to fame with "Blue Is the Warmest Colour", which won the Palme d'Or at the Cannes.
Stewart, 28, has always been a darling of the world's top film festival, appearing in the main competition in On the Road by Walter Salles in 2012 and Olivier Assayas' Clouds of Sils Maria and Woody Allen's Cafe Society in 2014.
Robert Guediguian, an activist filmmaker, achieved critical success with "Marius and Jeannette, which won the Prix Louis-Delluc in 1997".
Chen's credits include roles in 2013's The Grandmaster and 2015's The Assassin, Guédiguian received praise for his most recent film The House By the Sea, and Zvyagintsev won the Jury Prize for his film Loveless at the 2017 Cannes Film Festival.
"I do believe that if you have female storytelling, you also have more authentic female characters", she said during a press conference.
Nin, whose music is a mix of occidental pop, African and Afro-Cuban rhythms, received the Prize for Feminine Action by the African Women's League.