Stone chose to walk the red carpet with Billie Jean King, who she plays in her nominated film, "Battle of the Sexes".
Streep will attend with Ai-jen Poo, the director of the National Domestic Workers Alliance; Williams with Tarana Burke, the founder of the "me too" movement; and Watson will bring Marai Larasi, the executive director of Imkaan, a black-feminist organization.
Asked about her nomination in the best actress in a miniseries category, Sarandon told CNN she "completely forgot we had another reason for being here".
Laura Dern's date was Monica Ramirez, co-founder of Alianza Nacional de Campesinas, "who wrote the attractive letter of solidarity in Time magazine", said Dern of how she connected with Ramirez, representing female farmworkers.
"Black-ish" star Tracee Ellis Ross, who wore a black dress complete with black turban, said on the red carpet for the 75th Golden Globes, "Time's up on abuse, discrimination and the imbalance of power".
Susan Sarandon will bring Rosa Clemente, an organiser, political commentator and journalist who campaigns for media justice and voter engagement among youth of colour. If that movie sounds familiar, it's probably because you read about director Ridley Scott replacing supporting cast member Kevin Spacey with Christopher Plummer after Anthony Rapp accused Spacey of sexually propositioning him when he was 14 years old (Spacey was 26). "So it's now Emma's turn to do that".
The move is part of a widening effort by prominent Hollywood women, who formed the umbrella group Time's Up, to extend the focus on sexual harassment to women marginalised because of class, sexuality, ethnicity or race.