She began acting as a child, and starred in the action film Spy Kids: All the Time in the World (2011).

Blanchard was established as a teen idol following her breakthrough on Disney, and is noted for supporting various charitable causes and her outspoken views on social media.

Blanchard was born on October 14, 2001, in Los Angeles, California,[2][3] to Elizabeth and Mark Blanchard-Boulbol, who are yoga instructors.

[19] Max Nicholson of IGN agreed, writing that she had "the same go-getter spunk of predecessor Ben Savage, but she also nails the wide-eyed innocence that made Cory such a lovable lead in the original."

[25][26] In 2016, she was cast in the minor role of Veronica Kiley in Ava DuVernay's film A Wrinkle in Time,[27][28] an adaptation of the 1962 novel of the same name.

[30] In March 2019, Blanchard was cast as Alexandra Cavill in TNT/AMC's[31] Snowpiercer, a futuristic thriller series based on the 2013 South Korean-Czech film of the same name.

[39] Tomris Laffly of Variety called her "instantly likeable",[40] and Christy Lemire for RogerEbert.com wrote that both Blanchard and Cravalho "assert themselves confidently with more mature material while still bringing all that well-honed comic timing".

Most of her comments regarding these issues are posted via Twitter or Tumblr, and she has spoken at the UN Women and US National Committee's annual conference as part of #TeamHeForShe, a feminist campaign.

[43] She was inspired to do so after being harassed at age 12, and "started putting things on Twitter, Tumblr, and Instagram, because I realize that I have a following, and most of the people who watch our show, I would say, are girls.

"[48] In September 2024, Blanchard and 25 Palestinian and Jewish protestors were arrested outside the United Nations headquarters for disrupting the motorcade of Israeli prime minister Benjamin Netanyahu.

[52][53] Also in 2015, Rolling Stone included her on their list of "18 Teens Shaking Up Pop Culture" and said she was "not only a strong actress but has also made a name for herself as an outspoken feminist activist".