Elizabeth Anne Caplan (born June 30, 1982) is an American actress. Her first acting role was on the cult television series Freaks and Geeks (1999–2000). She received wider recognition with roles in the films Mean Girls (2004) and Cloverfield (2008), the latter of which earned her a nomination for the Saturn Award for Best Supporting Actress. Caplan has also starred on the television shows Related (2005–2006), The Class (2006–2007), and Party Down (2009–2010).

From 2013 to 2016, Caplan played Virginia E. Johnson on the Showtime series Masters of Sex, a role for which she received nominations for a Primetime Emmy, two Satellite Awards, and a Critics' Choice Award. In 2019, she portrayed Annie Wilkes in the Hulu anthology series Castle Rock. Her other film appearances include Hot Tub Time Machine, 127 Hours (both 2010), Save the Date, Bachelorette (both 2012), The Interview (2014), Now You See Me 2, Allied (both 2016), and Extinction (2018).