Emma Watson, Britney Spears and More Stars Celebrate International Women's Day -- See the Pics!

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The women of Hollywood are joining together to celebrate International Women's Day!

From Emma Watson and Britney Spears, to Madonna and Serena Williams, women everywhere are spreading girl power on social media.

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Watson, dressed in a red outfit in support of women, took to Twitter on Wednesday to reveal that she would be handing out feminist books. 

"Today I'm a red-striking ninja book-fairy out to spread some wise women's words @the_bookfairies #IWDOurSharedShelf #IWD #adaywithoutawoman," the Beauty and the Beast star wrote.

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Spears, meanwhile, paid tribute to the "fierce" women who inspire her, as Williams and Madonna shared their own posts in support of International Women's Day.

See more posts below:

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