The main character in a Diary of a Country Priest is the nameless narrator and the priest of the title. He is a young, often naive, thirty year old man from a working class family. He is just starting out as a priest in a small village in France called Ambricourt.

From the beginning, the priest paints himself as an unhappy person, struggling with himself and his negative mindset. He not only describes his village, and all villages for that matter, as "insignificant" but his parishioners as lonely and bored.

We can see them being eaten up by boredom and we can't do anything about it.

The parishioners include the priest's admirer, Seraphita Dumouchel; the bitter Dr. Maxence Delbende; the womanizing Count, the count's unhappy daughter, Mlle Chantal; the atheist Countess; and the Count's mistress, Mlle Louise.

The priest's negative and often intellectual manner, combined with his relative inexperience, generally makes it hard for him in spite of his best efforts to change things for the better, particularly in matters concerning poverty. Rich and influential people like Dr. Maxence tend to believe that the poor are to blame for their poverty.

In a way, my dear chap, I’m no friend of the poor. I’m not out for a new world. I’d rather they settled it without me — had it out with the powerful. But they don’t know how to begin, they make me ashamed of them.

The priest continues to work like a "cart horse," saying that he has the difficult task of visiting each family in the parish every three months but gets little support from his superior, the Curé de Torcy.

You’re a queer specimen! I shouldn’t think there’s another softy like you in the whole diocese! And you work like a cart-horse, sweating your guts out . . . Really His Grace must have been very hard up for priests to have given you the handling of a parish. Luckily a parish is solid enough — or you might break it.

It soon becomes apparent that the priest is gravely sick. The sicker he becomes, so too does his standing in the parish worsen, and rumors start to spread that he is conducting affairs with some of his female parishioners. The priest redeems himself somewhat, at least in his own eyes, by helping the Countess to die in spiritual peace.

Towards the end of the book, the priest finds out he has stomach cancer. He dies at the house of his friend, a former priest, M. Dufrety.