"38 countries are involved in the campaign, and it’s going to be the largest book fairy event ever - follow the hashtag to see where they are being hidden over the next few days! Do you believe in book fairies? #ibelieveinbookfairies," she added.
A second Instagram post shows the actress hiding copies of the classic in secret locations across London.
If you needed any more reason to love Watson, in the photos revealing the hidden books the actress is seen carrying a Bottletop bag - a company which creates chic, sustainable products using upcycled metal tabs.
For those of you hoping to get your mitts on one, you'll need to check out The Book Fairies Instagram page, as the company - which hides books across the globe for people to find - has revealed some of the locations where a copy of Little Women is patiently waiting to be read.
According to the grid, copies are lying in Toronto, Calgary, London and Hong Kong.
Aussies, take note. Watson has also hidden a number of books across Perth and Melbourne.
Famed for her love of reading, it's not the first time the actress has taken part in a Book Fairies event.
Back in 2017, Watson hid books by female authors around the world's largest cities to mark International Women's Day.
She also graced the headlines a few years back after hiding books in tube stations across London and New York for her book club, Our Shared Self.
So call your friends and make it your mission this weekend to bag a copy for yourself before sitting down to watch the highly-anticipated flick.
Little Women is in cinemas across Australia now.