Just Once a Great Lady () is a 1934 German comedy film directed by Gerhard Lamprecht and starring Käthe von Nagy, Wolf Albach-Retty and Gretl Theimer. Nagy plays a car saleswoman. The film's sets were designed by the art directors Otto Erdmann and Hans Sohnle. A separate French-language version A Day Will Come (1934) was also released, with Nagy reprising her role alongside Jean-Pierre Aumont.
In 1957 the film title was used for a West German remake of the 1932 film The Countess of Monte Cristo.