Armand is a tramp who has been a tramp for so long that he cannot remember what his last name is, or what he used to look like. He lives in Paris by the River Seine and wheels his meager belongings with him in a grocery cart. He always carries a black dress shoe that he found because it fits him perfectly and he is certain that one day he will find the matching shoe. Armand considers a spot under the bridge to be his own home since he has lived there for so long. However, one day he returns to find three children have set up home under "his" bridge and being a gentleman who does not enjoy children, he is extremely upset about this.
The oldest of the children, a little girl called Suzy, introduces herself and her siblings. Suzy, Paul and Evelyne Caleet are living under the bridge because their mother could not afford the rent after the children's father passed away. Mme Caleet wants to keep her family together so instead of temporarily putting the children into a charity home like the authorities want her to, she is sheltering them under the bridge whilst she works at a laundry to save enough money to rent a couple of rooms somewhere.
Armand decides to go and find food and at first is not very happy that the children want to accompany him. To his surprise he is already concerned for their welfare and realizing they are hungry decides to allow them to go with him. They go to a department store where a friend of Armand's is working as Father Christmas, the French version of Santa Claus. The children tell Father Christmas that they want a house for Christmas. To take their mind off of this subject Armand takes the children outside again and suggests they sing some Christmas carols. They soon draw a crowd and Armand collects small change in his beret for them. They collect enough to buy food and love feasting on hot roasted chestnuts from a roadside vendor.
When Armand and the children arrive back under the bridge the children's mother is home and is furious with Armand for taking them out. Discovering that they were singing for money she becomes even angrier and despite the protestations of the children shouts at him and tells him to leave. Armand leaves but later, returning to the bridge, sees two women in fit coats leaving and knows they are a threat to the Caleet family. He is correct and a tearful Madame Caleet tells him the women are coming back to the bridge the following day to take the children away. Armand leaps into action and visits an old friend who is a gypsy and persuades her to invite the Caleets to stay at the gypsy camp. Although she is enormously relieved to have a place to go Madame Caleet is uneasy about living with gypsies primarily because of their reputation for dishonesty; however the gypsies are kind and welcoming and a place is found for the Caleet family in one of the homes on wheels. Suzy, who likes school, is shocked that the gypsy children have no schooling and endeavors to teach them to read and write, but shortly the boys grow bored with these lessons and even her more devoted students question why they need to learn any of the things she is trying to teach them. Paul is more interested in learning the ways of the gypsies and wants to run away with them when they leave to go to Provence on the coast for the spring. Seeing how sad this makes Suzy, Armand tells Paul that he would bring too much attention to the gypsies as he has red hair.
After a couple of weeks the police come to the encampment looking for a man called Nikki. He is one of the gypsies who live there and is suspected of committing theft. Although Nikki is not there when the police come by, a visit from the police always means that it is time to move on. The gypsies leave and once again the Caleets have nowhere to go. Armand decides it is time for him to get a job and help to support this little family he has come to think of as his own. The Caleets help to make him presentable; he takes a bath and uses the new soap that Madame Caleet gave him for Christmas. Suzy shapes his beard and having luckily found the matching black dress shoe, Armand looks vastly different and very suitable for employment. His friend who worked as the department store's Father Christmas had told him of a job as a security guard but when he goes to apply he learns that it is actually acting as the manager in a big house where rooms are rented the owner wishes to employ a family man so that the family can live in the house in their own quarters. Armand is overjoyed and knows that Madame Caleet will be much happier working at home collecting rent from tenants and making sure the boarding house is well taken care of than she would ever be working in her current job at the laundry. As he walks back through the streets of Paris, Armand no longer feels like a tramp, but a working man of Paris, complete with dress shoes, and a last name.