Oprah Winfrey and Meryl Streep are among the big names putting political leaders “on notice” in an open letter led by international charity ONE.
The 140 signatories demand a commitment to help every girl get an education and for leaders to use their power to deliver “historic changes for women”.
Black Panther stars Letitia Wright and Chadwick Boseman have also signed.
Actors from the UK – including Michael Sheen, Thandie Newton and Natalie Dormer and the US – including Lena Dunham, Natalie Portman and Issa Rae – took part in the charity’s global call to action.
In the wake of recent movements against sexual harassment, Nashville star Connie Britton said in a statement: “We have seen an astounding level of attention paid to the harmful impacts that sexism and systemic gender inequality have on our society.”
The Emmy-nominated actress, who endorsed the letter, went on to say, “This year, it is my hope that all of us, especially our leaders, join in the fight for full equality.”
The letter describes poverty as sexist and said: “We won’t stand by while the poorest women are overlooked.”