Marches were held across Europe and other parts of the world as thousands gathered in Washington DC.
The idea for the march took off after a number of women posted on social media in the hours after Donald Trump's election.
Hundreds of groups quickly joined the cause, pushing a wide range of causes, including abortion rights, gun control, climate change and immigrant rights.
Other protests have taken place as far as Myanmar and Australia.
In Sydney, thousands of Australians marched in solidarity in Hyde Park.