Women's March 2018: Best Celebrity Reactions

One year ago, on Jan. 21, 2017, millions of women all around the world took to the streets for the historic Women's March, where they were advocating for human and women's rights. Dozens of celebrities turned out among the crowds in cities like Washington D.C., New York City, and Los Angeles, marching alongside their fans for an important cause.

Well, they're back at it again in 2018. This weekend, Women's Marches are being held in several major cities, and it should come as no surprise that many of Hollywood's A-listers are among the supporters at these huge events.

Amber Tamblyn joined the N.Y.C. Women's March, posting footage from the packed street on her Twitter and Instagram.

Tamblyn is one of hundreds of Hollywood women who recently launched the Time's Up movement to combat sexual harassment in the workplace, and her Instagram from the N.Y.C. March shows a group of people wearing shirts from the movement.

Actress Alyssa Milano also voiced her support on social media, writing on Twitter that "when women support each other... great things happen."

Singer Halsey announced on Twitter that she was speaking at the N.Y.C. March on Saturday, writing that she's "very honored" and "can't wait."

Eva Longoria is one of the many stars spoke at the L.A. Women's March, and she shared a poster for the event, writing, "Let's do this!"

See more reactions below and stay tuned for updates!