WATCH: The celebration first emerged from the labor movements in North America and Europe.
Today is a major cause for celebration -- it's International Women's Day!
And actors, actresses, musicians and more have all taken to social media to stand with women and celebrate them for all they contribute to the world.
Everyone, from Michelle Obama to Chris Hemsworth and Janet Jackson, has been sharing meaningful posts about equality, as well as fun messages of hope and inspiration. Here's what they had to say: