Kim Darby (born Deborah Zerby; July 8, 1947)[1] is an American actress best known for her roles as Mattie Ross in True Grit (1969) and Jenny Meyer in Better Off Dead (1985).

[5] Darby began acting at age 15; her first appearance was as a dancer in the feature film version of the earlier New York City's Broadway theater musicale play Bye Bye Birdie (1963), about a budding rock and roll music phenomenon singing and guitar-playing star, (modeled on the real-life career of famous Elvis Presley (1939-1977), beginning seven years before in 1956, when he gained national fame).

[6] Among her many feature films is the one that she is most famous for in American and Hollywood motion pictures history, is that of co-starring with legendary John Wayne and Glen Campbell, in the Western classic True Grit (first version of 1969), in which she played "Mattie Ross", a precocious, unusually confident 14-year-old Arkansas frontier girl (when she was actually 21 years old), pursuing the murderer who killed her beloved father and his gang into the adjacent lawless frontier of the federal Indian Territory (future Oklahoma), in the mid-1870s.

Darby also appeared about this time on The Eleventh Hour, The Fugitive, The Donna Reed Show, Ironside, and in the first season of Star Trek as the title character in "Miri.

Some of her subsequent television roles included guest appearances on Crazy Like a Fox, Thriller, Family, The Love Boat, The Streets of San Francisco, Riptide, and Becker.

[11] Darby also appeared in the 1999 The X-Files episode "Sein und Zeit" as a woman who confessed to the murder of her son, a boy who disappeared under circumstances similar to those being investigated by the lead characters, Fox Mulder and Dana Scully.