Hollywood stars celebrated the power of the Me Too movement as hundreds of thousands of protesters joined Women’s Marches on the anniversary of Donald Trump’s inauguration as US president.

Scarlett Johansson, Viola Davis and Eva Longoria were among those to address an estimated 700,000-plus crowd in Downtown Los Angeles on Saturday.

The weekend marks a year since more than one million people worldwide rallied on Mr Trump’s first day in the White House and comes at a time of reckoning for many powerful men in Hollywood and other industries over their treatment of women.

Johansson, wearing a Time’s Up top, told marchers how the Harvey Weinstein revelations led her to consider how she was treated as a young actress.

Viola Davis speaking to the crowd in Los Angeles
Viola Davis speaking to the crowd in Los Angeles (Jae C. Hong/AP)

Many of her relationships, both personal and professional, had power dynamics “so off” that she let herself be “degraded”, she said.

“I stand before you as someone who is empowered not only by the curiosity about myself and by the active choices that I’m finally able to make and stand by, but by the brightness of this movement, the strength and the unity that this movement has provided,” she said.

“It gives me hope that we are moving toward a place where our sense of equality can truly come from within ourselves.”

Davis shared her own experiences to echo the march organisers’ sentiment to encourage people to sign up to vote in November’s mid-term elections, which could deal a blow to the president.

“I’m always introduced as an award-winning actor but my testimony is one of poverty, my testimony is one of being sexually assaulted and very much seeing a childhood that was robbed from me,” Davis said.

“I know that the trauma of those events are still with me today and that’s what drives me to the voting booth, that’s what allows me to listen to the women who are still in silence.”

Longoria encouraged protesters to seize the Me Too momentum to fight for equality and decried the “sexist, racist rhetoric” coming out of the White House.

Eva Longoria addressing the crowds
Eva Longoria addressing the crowds (Jae C. Hong/AP)

“As we build upon the momentum of Me Too and Time’s Up in this movement, we women have the world’s attention so let’s seize this moment and catalyse a permanent and cultural shift towards fairer and equal treatment in the workplace,” she said.

Alfre Woodard said that people must reach across boundaries to fight for a common cause in this “dangerous and baffling hour”.

As the thousands took to the streets, Mr Trump tweeted that it was a “perfect day” for women to celebrate the “economic success and wealth creation” of his first year in the White House.

Meanwhile his main rival in the 2016 election, Hilary Clinton, urged the marchers to demonstrate their will at the ballot box.

“In 2017, the Women’s March was a beacon of hope and defiance,” she wrote on Twitter.

“In 2018, it is a testament to the power and resilience of women everywhere. Let’s show that same power in the voting booth this year.”

Anti-Trump sentiments were prominent among the placards, and so were pro-immigrant messages and those in favour of women’s rights, including one reading “Girls just want to have fun-damental rights”.

Womens March Los Angeles
Protesters gather at Grand Park in Los Angeles. (AP/Jae C Hong)

There was also a continued outrage over Mr Trump’s policies and alleged pre-election behaviour, which includes denied claims of sexual assault by multiple women and his boasting of grabbing women “by the pussy”.

The pink, pointy-eared “pussy hats” used to mock the commander-in-chief made a popular return.

Demonstrations also took place in cities including New York and Washington DC on Saturday.

UK cities will hold marches on Sunday, including a London demonstration in support of Time’s Up.

Meanwhile organisers of a rally in Las Vegas will hope to register one million voters ahead of the midterms.