The story is set in 1912. Monsieur Ladmiral (Ducreux), an old painter, lives in the country with his servant Mercédès. His son Gonzague (Aumont), his daughter-in-law and his grandchildren pay him a visit, as they usually do. After lunch, Monsieur Ladmiral's daughter Irène (Azéma) comes to his home too.
A Sunday in the Country provides examples of:
- Fantasy Sequence:
- At some point, Monsieur Ladmiral imagines that he is talking to his late wife.
- Later, Gonzague imagines that his father is dead.
- Irène also imagines that she is talking to her late mother.
- The Edwardian Era: The story is set in 1912. The telephone is in use. Monsieur Ladmiral talks about the time where he saw a photograph for the first time. Irène owns an automobile, which is a new thing.
- Exactly What It Says on the Tin: The film is about some people who spend a Sunday in the country.
- Extremely Short Timespan: The action of the movie takes place during one day, from dawn to dusk.
- The Film of the Book: The film is based on a 1945 book by Pierre Bost, Monsieur Ladmiral va bientôt mourir.
- Foolish Sibling, Responsible Sibling: Gonzague is very serious: he has a stable job and a strong family. He visits his father frequently. Her sister Irène does not want to get married. She has a secret lover. Her job is not stable, but she spends a lot of money (she owns a motor car). She visits his father rarely.
- Genki Girl: Irène is cheerful and full of energy. She constantly moves quickly. She does not stop talking (so that it is difficult for her father to say something).
- Happy Flashback: A flashback shows the Ladmirals having a picnic in the garden when Gonzague and Irène were children and their mother was alive.
- Insistent Appellation: Monsieur Ladmiral insists on calling his son "Gonzague", an aristocratic given name, whereas his servant and Gonzague's wife call him "Édouard", a more common name.
- The Lost Lenore: The wife of Monsieur Ladmiral is dead. He often talks about her. There is even a Fantasy Sequence where he imagines that he talks to her.
- Narrator: At several points, a narrator gives some additional information about the characters and their thoughts.
- Spirited Young Lady: Irène is young. Her family is rich. She is witty and confident. She likes speed and automobiles, which are "unladylike" things. She is independent and self-sufficient. She does not want to get married. She is outspoken and bold. She avoids going so far beyond the rules of her society that she would be labelled disreputable: she has a secret lover, but she does not tell her father about him.