Kathleen Hanna (born November 12, 1968) is an American singer, musician and pioneer of the feminist punk riot grrrl movement, and punk zine writer. In the early-to-mid-1990s, she was the lead singer of feminist punk band Bikini Kill, and then fronted the electropunk band Le Tigre in the late 1990s and early 2000s. Since 2010, she has recorded as the Julie Ruin.

In 2009, Hanna made her zines, art pieces, photography, video, music, journals, and other material which focus on the early formation of the Riot Grrrl movement available at the Fales Library at New York University. A documentary film about Hanna was released in 2013 by director Sini Anderson, titled The Punk Singer, detailing Hanna's life and career, as well as revealing her years-long battle with Lyme disease. Hanna is married to Adam Horovitz of the Beastie Boys.