International Day of the Girl: Jessica Biel, Salma Hayek among stars taking part in 'Girl Effect' challenge

Oct. 11 is International Day of the Girl, and several of Hollywood’s biggest names are sharing their stories in honor of the holiday.

Created by UNICEF, the International Day of the Girl campaign works to inspire adolescent girls to amplify their voices and stand up for their rights across the globe. This year’s theme, “My Voice, Our Equal Future,” focuses on the demands of adolescent girls to live free from gender-based violence, harmful practices like child marriage and genital mutilation, and HIV and AIDS. It also seeks to inspire girls to learn new skills that target the type of future they choose, and to become leaders as a generation of activists who can accelerate social change.

Several famous faces hopped online to participate in the event while using the hashtag #TheGirlEffect, citing the Girl Effect campaign to empower young girls through social media content.

Actress Jessica Biel shared a throwback photo of herself as a young girl on the soccer field, writing “society told me I was SUPPOSED TO be nice, be pretty, be sweet, be feminine. Instead, I CHOSE TO own my strength, cultivate my mind, and embrace my power.

“At a young age, so many girls are taught to be comfortable walking two steps behind their male peers. As someone who always identified in mind and body as an athlete — that never made sense to me,” she continued. “Women are powerful and that’s a great thing. Even though it scares the s*** out of people. While the gender stereotypes have evolved and we’ve come a long way — it’s still so important for little girls everywhere to recognize that they are capable of everything — and more. We have to teach all children equality so that one day, girls will be represented EVERYWHERE that decisions are made. Because when one girl finds her power to make different choices that change her life, it inspires others to do the same … and THAT changes the world.”

Salma Hayek also shared her own story, looking back on how she defied expectations regarding her career.

“I was SUPPOSED TO be a soap star in Mexico, but instead I CHOSE TO be a film star and an activist in the world,” she wrote, encouraging followers to share their own stories, “because when a girl find her power to make different choices that change her life, it inspires others to do so too.”

Demi Moore reflected on her experience of being pregnant, saying how attractive she felt throughout her pregnancy. Wanting to highlight her changing body, she asked a photographer to capture the power she felt.

“I seized an opportunity where I had to do a photo shoot for Vanity Fair, and I asked the photographer that if we were going to do this, that we do it in a way that reflected how I really felt about myself, which was beautiful, and powerful, and sexy,” Moore said in a video post.

Ultimately, Moore posed naked for the magazine cover, which went on to become a major success.

“Society told me I was SUPPOSED TO to hide my pregnant body. Instead, I CHOSE TO celebrate it,” wrote Moore.

Supermodel Anne V also posted in honor of the holiday.

“SUPPOSE TO: be a wife, a mother, always be at a mercy of men,” she wrote. “CHOSE TO: listen to my intuition, be brave, bold and make all my dreams come true.”

Other stars marked International Day of the Girl separate from the #TheGirlEffect campaign. Michelle Obama shared a passionate post about her own organizations, and how she’s working toward providing young women with educational opportunities.

“These past months have been an anxious and difficult time for all young people, and for millions of girls around the world the question isn’t when they will return to school, or if they can manage it virtually — it’s if they’ll ever return at all,” she wrote. “And that’s heartbreaking. Our world just can’t afford to miss out on their talents and their ideas.”

Jennifer Garner joined in with a post showing her at a Save the Children event in Arkansas.

“If you want to change the world, educate a girl,” she captioned the photo, which showed her surrounded by little girls.

David Beckham also joined in, sharing a post of himself surrounded by young women.

“All girls, wherever they are in the world, should have the chance to learn and to achieve their potential. Our daughters deserve just the same opportunities as our sons,” wrote Beckham. “Today on #DayoftheGirl we celebrate girls all around the world who are working hard to make a positive change in their lives and communities.”

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