Cynthia Jane Williams was an American actress. She is best known for her role as Shirley Feeney on the television sitcoms Happy Days (1975–1979), and Laverne & Shirley (1976–1982). She also appeared in American Graffiti (1973), The Conversation (1974), Mr. Ricco (1975), and More American Graffiti (1979).

Laverne & Shirley is an American sitcom television series that ran for eight seasons on ABC from January 27, 1976, to May 10, 1983. A spin-off of Happy Days, Laverne & Shirley starred Penny Marshall and Cindy Williams as Laverne DeFazio and Shirley Feeney, two friends and roommates who work as bottle-cappers in the fictitious Shotz Brewery in late 1950s Milwaukee, Wisconsin. From the sixth season onwards, the series' setting changed to mid-1960s Burbank, California. Michael McKean and David Lander co-starred as their friends and neighbors Lenny Kosnowski and Andrew "Squiggy" Squiggman, respectively; along with Eddie Mekka as Carmine Ragusa, Phil Foster as Laverne's father Frank DeFazio, and Betty Garrett as the girls' landlady Edna Babish.