Jennifer Diane Lewis (born January 8, 1976) is an American singer-songwriter, musician, and actress. She was the lead singer, rhythm guitarist, and keyboardist for the indie rock band Rilo Kiley.

Lewis gained prominence in the 1980s as a child actress, appearing in the films Troop Beverly Hills (1989) and The Wizard (1989) and the television series Brooklyn Bridge (1991–93). In the mid-1990s, Lewis semi-retired from acting to focus on her musical career, and formed Rilo Kiley in 1998 with fellow former child actor Blake Sennett. Rilo Kiley released four albums before they disbanded in 2014.

Lewis has released five solo albums: Rabbit Fur Coat (2006), Acid Tongue (2008), The Voyager (2014), On the Line (2019), and Joy'All (2023). In addition to Rilo Kiley and her solo career, Lewis has been a member of The Postal Service, Jenny & Johnny, and Nice as Fuck.