Kim Darby (born July 8, 1947) is an American actress.
Darby was born Deborah Zerby in Los Angeles, California, the daughter of professional dancers Inga and Jon Zerby. Her father insisted on calling her "Derby" Zerby because he believed it was a great stagename.
Darby began acting at age fifteen and has appeared in many films and television shows. Her first appearance was as a dancer in the 1963 film Bye Bye Birdie. Among her best known roles are True Grit (1969) when she was twenty-one years old, Better Off Dead (1985), and Halloween: The Curse of Michael Myers (1995). After she starred in True Grit, film critics predicted that she was at the beginning of a long career as a great actress. In fact, she has made almost no films of note since. This has caused some critics to put her in the same category as Bo Derek (in 10) and Maria Schneider (in Last Tango in Paris), because all three actresses made spectacular splashes in their first films, but never acted in successful films again.