Jennifer Diane Lewis (born on January 8, 1976 in Las Vegas, Nevada) is an American singer, musician, and actress.

Lewis is a member and primary vocalist of the indie rock band Rilo Kiley, and has released two solo albums. She was a child actress.

Lewis made her professional debut in a Jell-O commercial. She was featured in the short-lived 1986 Lucille Ball sitcom Life With Lucy, where she was cast as one of Lucy's grandchildren. She also had small roles on such TV shows as The Twilight Zone, Baywatch, Golden Girls, Growing Pains, Just the Ten of Us, Roseanne, Mr. Belvedere, and Brooklyn Bridge.