Shelley Long is an American actress, singer, and comedian. For her role as Diane Chambers on the hit sitcom Cheers, Long received five Emmy nominations, winning in 1983 for Outstanding Lead Actress in a Comedy Series. She also won two Golden Globe Awards for the role. Long reprised her role as Diane Chambers in three episodes of the spin-off Frasier, for which she received an additional guest star Emmy nomination. In 2009, she began playing the recurring role of Dede Pritchet on the ABC comedy series Modern Family.

Diane Chambers is a fictional character in the American television situation comedy show Cheers, portrayed by Shelley Long and created by Glen and Les Charles. After her fiancé Sumner Sloan abandons her in the Cheers bar in the pilot episode, Diane works as a bar waitress. She has an on-off relationship with the womanizing bartender Sam Malone and a one-year relationship with Frasier Crane, who later becomes a main character of the series and Frasier. When Long left the series during the fifth season, the producers wrote her character out. After that, they added her permanent replacement Rebecca Howe, a businesswoman played by Kirstie Alley, in the sixth season. Shelley Long made a special guest appearance as Diane in the series finale, as well as in Frasier as a one-time figment of Frasier's imagination, and as the actual Diane in the crossover episode "The Show Where Diane Comes Back".