"I'm hiding copies all over Paris!" the actor best known for playing Hermione Granger said on Twitter.
Atwood's 1985 novel -- which has now been turned into a hit television series starring Elisabeth Moss of "Mad Men" fame -- is about a dystopian world where women are reduced to being the child-bearing slaves of male masters.
The British actress -- a goodwill ambassador for the UN on women's rights -- left about 100 copies of the book in various spots across the French capital, according to the website of the Livres Hebdo magazine.
Watson, 27, set up the feminist reading group "Our Shared Shelf" last year which has now nearly 200,000 members.
She carried out a similar exercise across the Channel in November, leaving copies of Maya Angelou's memoir "Mom & Me & Mom" on the London Underground, and in New York in March.
The idea is that readers might chance upon the books and be inspired by them.
To make sure all the books are found, the Twitter account "The Book Fairies" has been leaving clues as to where the copies were left.