Lenore Lonergan (2 June 1928 – 17 August 1987) was a stage and film actress during the 1930s and 1940s. Lonergan, whose grandfather, father and brother also were actors, made her stage debut at the age of 6, in Mother Lode, starring Melvyn Douglas. In 1939, she played Dinah Lord, the younger sister of Katharine Hepburn's Tracy Lord, in Phillip Barry's comedy The Philadelphia Story. In The New York Times, Brooks Atkinson wrote of Miss Lonergan's performance, As the brat of the family, Lenore Lonergan, of a famous theatrical tribe, acts with a stout sort of humor that suits her groaning little figure.
Miss Lonergan also played juvenile roles in Junior Miss, by Jerome Chodorov and Joseph Fields, and in Dear Ruth, by Norman Krasna. She appeared in Crime Marches On,Fields Beyond, and in the film Tom, Dick and Harry, among others.