Reese Witherspoon, Lupita Nyong'o and More Stars Celebrate International Women's Day

Todd Williamson/Getty Images for Vanity Fair

Witherspoon spent the day with 'Black Panther' star Danai Gurira at the UN.

Happy International Women's Day!

People all over the world flocked to social media to celebrate International Women's Day on Thursday, celebrities included. Stars like Reese Witherspoon, Lupita Nyong'o, Alyssa Milano, Michelle Obama and more took to Twitter to give a special shout-out to women.

Witherspoon teamed up with Black Panther star Danai Gurira to commemorate the day at the UN, where they spoke about women's rights and the Time's Up movement. 

"Thank you for using this day to provoke such important conversation about women! #IWD2018," the 41-year-old actress wrote on Twitter. 

Gurira's Black Panther co-star, Nyong'o, meanwhile, shined a spotlight on Gurira's organization, Love Our Girls. "The Pantherpuff Girls are here for #InternationalWomensDay! We must see, respect & honor the different kinds of strength that women possess," she wrote. "Give a voice to women around the world and take the pledge for @DanaiGurira’s #LoveOurGirls:  Art: @PrimePremne." 

See more tweets below: 

Women have brought their stories to the forefront over the past year, with movements like Me Too and Time's Up making big statements across news cycles and awards shows. See more in the video below.