"It's been a heartbreaking time to be both a woman and an immigrant in this country," the Ugly Betty alum, the daughter of Honduran immigrants, told the crowd. "Our dignity, our character, our rights have all been under attack and a platform of hate and division assumed power yesterday."
"We march today for our families and our neighbors, for our future, for the causes that we claim and the causes that claim us," Ferrera said. "We march today for the moral core of this nation, against which our new president is waging a war."
Johannson talked about the importance of women's health, Planned Parenthood and access to reproductive services.
"President Trump, I did not vote for you," she said. "That said, I respect that you are our President-elect and I want to be able to support you but first I ask that you support me, support my sister, support my mother...support my daughter who may actually, as a result of the appointments you have made, grow up in a country that is moving backwards, not forward and who may potentially not have the right to make choices for her body and her future that your daughter Ivanka has been privileged to have."
"I ask you to support all women and our fight for equality in all things," she said, adding, "I pledge my relentless devotion to women's healthcare initiatives. I will not stop fighting to make basic women's healthcare available to all."
Other celebrities who spoke at the Women's March on Washington included Madonna, feminist icon Gloria Steinem, Michael Moore, Alicia Keys, Janelle Monáe and Ashley Judd.
Katy Perry announced on Instagram she would be marching with sister Angela Hudson.
"Marching with SO many sisters today but my heart is most proud to march with my blood sister, Angela, who has always been my guardian angel," she wrote. "We should all be guardians for each other. I march today because I am not afraid anymore and I hope I can be an example of fearlessness and resilience. I will not let anyone suppress me, silence me or clip my wings."
"For a long time I misunderstood the true definition of being a feminist, but now that I know, I am empowered!" she said. "I am indisputably a feminist. I am here today to break the cycle of suppression and inequality. I stand with you all! ♥#whyimarch @womensmarch."
Women's rights marches also took place in cities such as New York City, Los Angeles, Boston, Chicago, Denver, Las Vegas and Park City, Utah, where many celebs are in town for the 2017 Sundance Film Festival.
Cyrus marched in Los Angeles, where the subways were extraordinarily packed with participants rushing to get to the protest. Other celebrity attendees included Joseph Gordon-Levitt, pregnant Lauren Conrad and Willow Smith, E! News has learned. Holly Madison marched in Las Vegas.
In Park City, Charlize Theron and Maria Bello marched together alongside women holding pink signs supporting Planned Parenthood and women's rights. Many of the participants across the country wore pink wool hats with kitty ears.
"When they punch you in the p---y, Punch them back harder with your p---y power!" Bello shouted, according to Variety reporter Jim Rainey.
Mary Steenburgen, Jurnee Smollett-Bell, Jennifer Beals and Laura Dern also took part in the protest, as did Teigen's husband, singer John Legend, and Benjamin Bratt.
