International Women's Day 2015
Millions of people around the world celebrated International Women's Day (IWD) on 8 March Getty

Millions of people around the world celebrated International Women's Day on 8 March, honouring the economic, political and social achievements of women.

Celebrities including Shakira, Kerry Washington, Cara Delevingne, Madonna and Ariana Grande took to social media to show their support using #InternationalWomensDay.

On Intl Women's day I want to highlight the power of education as a catalyst to transform the lives of millions of girls around the world.

— Shakira 🤫 (@shakira) March 8, 2015

Repost! Thank you Hilary Clinton! Happy International Womens Day! ❤️ #rebelheart

— Madonna (@Madonna) March 8, 2015

We must stand up for Women's rights, education and health. Join me to make change happen. #IWD2015

— Victoria Beckham (@victoriabeckham) March 8, 2015

“The question isn’t who’s going to let me; it’s who is going to stop me.”
- Ayn Rand. Happy International Women's Day

— P!nk (@Pink) March 8, 2015

Wearing purple this afternoon for International #WomensDay & I'll be hanging with a bunch of women friends sooo pretty excited all around! 😜

— kerry washington (@kerrywashington) March 8, 2015

#InternationalWomensDay 🙌 to the amazing, talented, fragile, strong, loving, giving, funny, deep, magical & inspiring women in my life!

— Kylie Minogue (@kylieminogue) March 8, 2015

Happy Women's Day! Here's to the women who build each other up and encourage each other to be themselves as opposed to tear each other down💭

— Ariana Grande (@ArianaGrande) March 8, 2015

Today & every day I'm grateful for THE most inspirational woman in my life. My beloved Momma. #InternationalWomensDay

— Robin Roberts (@RobinRoberts) March 8, 2015
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Happy #internationalwomensday

A post shared by Cara Delevingne (@caradelevingne) on

Meanwhile, last year in September, actress and UN Women Goodwill Ambassador Emma Watson had asked men to get involved with gender equality, during the HeForShe campaign.

"I was appointed six months ago and the more I have spoken about feminism the more I have realized that fighting for women's rights has too often become synonymous with man-hating," she said.

The Harry Potter star added: "If there is one thing I know for certain, it is that this has to stop. For the record, feminism by definition is: 'The belief that men and women should have equal rights and opportunities. It is the theory of the political, economic and social equality of the sexes.'"