Update 8.50pm: US president Donald Trump tweeted that it was a "perfect day" for women to march to celebrate the "economic success and wealth creation" of his first year in office - while women across America rallied against him and his policies.
Beautiful weather all over our great country, a perfect day for all Women to March. Get out there now to celebrate the historic milestones and unprecedented economic success and wealth creation that has taken place over the last 12 months. Lowest female unemployment in 18 years!— Donald J. Trump (@realDonaldTrump) January 20, 2018
However, people participating in rallies and marches in the US and around the world denounced Mr Trump's views on immigration, abortion, LGBT rights, women's rights and more.
The march in Washington, DC, today had the feel of a political rally when US senator Kirsten Gillibrand and US congresswoman Nancy Pelosi, both Democrats, urged women to run for office and vote to oppose Mr Trump and the Republicans' agenda.
"We march, we run, we vote, we win," Ms Pelosi said, to applause.
"The buck stops here. Happy anniversary, Mr. President, your wish came true. You wanted to shut down -- the Trump shutdown is all yours," Rep. Nancy Pelosi says https://t.co/oNqS9I1c00 pic.twitter.com/wApfS8PEGk— CBS News (@CBSNews) January 20, 2018
Who wants to tell him? https://t.co/ZIWZvVkMCO— Nancy Pelosi (@SpeakerPelosi) January 20, 2018
Thousands of people turned out for the rally at Lincoln Memorial and a march from the National Mall to Lafayette Park. It was one of many around the US and the world in support of female empowerment.
Thousands of people gathered in Cleveland, Richmond, Virginia, Philadelphia, New York, Austin, Texas, and elsewhere.
In Palm Beach, Florida, home to Mr Trump's Mar-a-Lago estate, several hundred people gathered carrying anti-Trump signs as they prepared to march.
Across the globe, people hit the streets on the anniversary of Mr Trump's inauguration, marching against his policies and in support of the #MeToo movement against sexual assault and harassment.
In Palm Beach, a group of women wearing red cloaks and white hats like the characters in the book and TV show The Handmaid's Tale marched in formation, their heads bowed.
— Taylor Goldenstein (@taygoldenstein) January 20, 2018
In Los Angeles, organisers predicted thousands of people, including state officials and celebrities, would march to City Hall.
Activists in New York said the march was important because basic rights for women, immigrants and others are under attack.
In Chicago, thousands of people gathered in Grant Park. Fawzia Mirza drew cheers from the crowd as she kicked off the event with a reference to the partial government shutdown, which began hours earlier.
“It’s very important to know that this is the ‘Women’s March Chicago,’ but this is not just for women to show up,” activist Fawzia Mirza said. https://t.co/Sk1VpZLYQz #WomensMarch2018 #MarchToThePolls pic.twitter.com/7Q6l9S9SM6— Chicago Sun-Times (@Suntimes) January 16, 2018
"When the government shuts down, women still march," she said.
Earlier, activists gathered in Rome to denounce violence against women and express support for the #MeToo movement. They were joined by Italian actress and director Asia Argento, who made headlines after alleging in 2017 she had been sexually assaulted by Hollywood producer Harvey Weinstein in the 1990s. She spoke up about the criticism she received after revealing her own experiences of abuse.
The 2017 rally in Washington, DC, and hundreds of similar marches created solidarity for those denouncing Trump's views on abortion, immigration, LGBT rights and more. Millions of people around the world marched during last year's rallies, and many on Saturday thought about all that has happened in the past year.
The Republican president delivered new support to the anti-abortion movement he once opposed, speaking by video to thousands of activists at the annual March for Life on Friday.
Among the goals of this year's march are getting more Democrats to run for public office and bolstering voter registration.
Update 7.30pm: Protesters march against Trump on first anniversary of inauguration
Protesters around the world are marking the first anniversary of President Donald Trump’s inauguration by marching against his policies, and also in support of the #MeToo movement against sexual assault and harassment.
A protest in New York is among more than 200 such activities planned for the weekend around the world.
By mid-morning, dozens of people had gathered in Chicago, Los Angeles, Denver and Raleigh, North Carolina. In Philadelphia, many marchers wore pink cat-ear hats as a show of solidarity, while others carried signs stating opposition to Mr Trump and his policies.
Earlier, activists gathered in Rome to denounce violence against women and express support for the #MeToo movement. They were joined by Italian actress and director Asia Argento, who made headlines after alleging in 2017 she had been sexually assaulted by Hollywood producer Harvey Weinstein in the 1990s.
So much love, what a beautiful sight!!!
This is what UNITED looks like!!!
Hear us ROAR!!!
The 2017 rally in Washington, DC, and hundreds of similar marches were held denouncing Mr Trump’s views on abortion, immigration, LGBT rights and more. Millions of people around the world marched during last year’s rallies.
In New York, scheduled speakers included Ashley Bennett, a Democrat who was elected Atlantic County, New Jersey, last November.
Chicago Women's March has already EXCEEDED last year's crowd:January 20, 2018
Ms Bennett defeated the Republican incumbent John Carman, who had mocked the 2017 women’s march in Washington, DC, with a Facebook post asking whether the women would be home in time to cook dinner.
One of the goals of this year’s march is to prompt more Democrats to run for public office and bolstering voter registration.
In Rome, the 42-year-old Argento addressed the criticism she received after she had spoken up about the abuse she suffered.
She told the rally: "Women are scared to speak, and because I was vilified by everything I said, I was called a prostitute for being raped.
"I wonder how women who received such violence would find the courage to come out as I did, when they saw what happened to me, so I am here to assess the necessity of women to speak out and change things."
Argento was strongly criticised by many Italian media and Italian women for not speaking out earlier and was hounded on Twitter with accusations that she had sought trouble.
Last year’s march in Washington sparked debate over inclusion, with some transgender minority women complaining that the event seemed designed for white women born female. Some anti-abortion activists said the event did not welcome them.
Organisers for the Sunday rally are striving for greater inclusion this year, with Latina and transgender female speakers, said Carmen Perez, another co-chair of the 2017 Washington march. Women in the US illegally, sex workers and those formerly incarcerated are also welcome, she said.
Linda Sarsour, one of the four organisers of last year’s Washington march, said Las Vegas had been pinpointed for a major rally because it is a strategic swing state that gave Hillary Clinton a narrow win in the 2016 presidential election and will have one of the most competitive Senate races in 2018.