Kate Siegel (/ˈsiːɡəl/; born August 9, 1982) is an American actress and screenwriter. Siegel is best known for her collaborations with her husband, filmmaker Mike Flanagan, appearing in his horror films Oculus (2013), Hush (2016), which she also co-wrote, Ouija: Origin of Evil (2016), and Gerald's Game (2017). Siegel also starred as Theodora Crain in the Netflix supernatural horror series The Haunting of Hill House (2018), and her voice acting has appeared on the horror podcasts Calling Darkness and The NoSleep Podcast.
Siegel attended St. Andrew's Episcopal School in Maryland and graduated from Syracuse University in 2004.
Siegel made her acting debut in the film The Curse of The Black Dahlia, which was released on January 23, 2007. That same year she went on to star in Hacia La Oscuridad which had its world premiere at the Tribeca Film Festival on April 28, 2007. She also appeared in Steam alongside Ruby Dee and Chelsea Handler. In 2008, Siegel appeared in the short film Knocked Down which was directed by Ted Collins. In 2009, she made her television debut in Ghost Whisperer as Cheryl. In 2010, she appeared in Numb3rs as Rachel Hollander. She then appeared in an episode of Castle. That same year she appeared in the drama-thriller Wedding Day.