Emma Bovary is the novel's protagonist and is the main source of the novel's title (Charles's mother and his former wife are also referred to as Madame Bovary, while their daughter remains Mademoiselle Bovary). She has a highly romanticized view of the world and craves beauty, wealth, passion, as well as high society. It is the disparity between these romantic ideals and the realities of her country life that drive most of the novel, most notably leading her into two extramarital love affairs as well as causing her to accrue an insurmountable amount of debt that eventually leads to her suicide.
Charles Bovary, Emma's husband, is a very simple and common man. He is a country doctor by profession, but is, as in everything else, not very good at it. He is in fact not qualified enough to be termed a doctor, but is instead an officier de santé, or "health officer". Charles adores his wife and finds her faultless, despite obvious evidence to the contrary. He never suspects her affairs and gives her complete control over his finances, thereby securing his own ruin. Despite Charles's complete devotion to Emma, she despises him as he is the epitome of all that is dull and common.
Rodolphe Boulanger is a wealthy local man who seduces Emma as one more addition to a long string of mistresses. Though occasionally charmed by Emma, Rodolphe feels little true emotion towards her. As Emma becomes more and more desperate, Rodolphe loses interest and worries about her lack of caution. After his decision to escape with Emma he resigns and feels unable to handle it especially with the existence of her new daughter, Berthe.
Léon Dupuis is a clerk who has an affair with Madame Emma Bovary. He is the second person Emma has an affair with, after Rodolphe Boulanger.
Monsieur Lheureux is a manipulative and sly merchant who continually convinces people in Yonville to buy goods on credit and borrow money from him. Having led many small businesspeople into financial ruin to support his own business ambitions, Lheureux lends money to Charles and plays Emma masterfully, leading the Bovarys so far into debt as to cause their financial ruin and Emma's subsequent suicide.
Monsieur Homais is the town pharmacist. He is vehemently anti-clerical and an atheist. He also practices medicine without a license and although he pretends to be Charles Bovary's best friend, he actively undermines Bovary's medical practice by luring away his patients and by setting Charles up to attempt a difficult surgery, which fails and destroys Charles's professional credibility in Yonville.
The wife of Monsieur Homais, Madame Homais, is a simple woman whose life revolves around her husband and four children.
Justin is Monsieur Homais' apprentice and second cousin. He had been taken into the house from charity and was useful at the same time as a servant. He harbors a crush on Emma. At one point he steals the key to the medical supply room and is tricked by Emma into opening a container of arsenic so she can "kill some rats keeping her awake". She however eats the arsenic herself, much to his horror and remorse.