Lake Siegel Bell (born March 24, 1979) is an American actress, director, and screenwriter. She has starred in various television series, including Boston Legal (2004–2006), Surface (2005–2006), How to Make It in America (2010–2011) and Childrens Hospital (2008–2016), and in films including Over Her Dead Body (2008), What Happens in Vegas (2008), It's Complicated (2009), No Strings Attached (2011), Million Dollar Arm (2014), No Escape (2015),The Secret Life of Pets (2016), and Home Again (2017).

She wrote and directed the short film Worst Enemy, which debuted at the Sundance Film Festival in 2012, followed by her 2013 feature film directing debut In a World..., in which she also starred. In 2017 she directed, wrote, co-produced and starred in I Do... Until I Don't.