Madison Nicole Ziegler (born September 30, 2002) is an American actress and dancer. She was initially known for appearing in Lifetime's reality show Dance Moms from 2011 (at age 8) until 2016. From 2014, she gained wider recognition for starring in a series of music videos by Sia, beginning with "Chandelier" and "Elastic Heart", which have in total attracted more than 5 billion views on YouTube. Ziegler has appeared in films, television shows, concerts, advertisements and on magazine covers.

Ziegler was a judge on the 2016 season of So You Think You Can Dance: The Next Generation and toured with Sia in North America and Australia in 2016. Her 2017 memoir, The Maddie Diaries, was a New York Times Best Seller. Her film roles include Camille Le Haut in the animated film Ballerina (2016), Christina Sickleman in The Book of Henry (2017), the title role in Music (2021), Mia Reed in the high school drama The Fallout (2021) and Velma in Steven Spielberg's 2021 West Side Story.

Ziegler was included by Time magazine on its list of the "30 most influential teens" in each year from 2015 to 2017. She was included in the 2023 Forbes 30 Under 30 list in the Hollywood & Entertainment category. Her social media presence includes an Instagram account with more than 13 million followers.