The Misanthrope, or the Cantankerous Lover (French: Le Misanthrope ou l'Atrabilaire amoureux; French pronunciation: [lə mizɑ̃tʁɔp u latʁabilɛːʁ amuʁø]) is a 17th-century comedy of manners in verse written by Molière. It was first performed on 4 June 1666 at the Théâtre du Palais-Royal, Paris by the King's Players.

The play satirizes the hypocrisies of French aristocratic society, but it also engages a more serious tone when pointing out the flaws that afflict all humans. The play differs from other farces of the time by employing dynamic characters like Alceste and Célimène as opposed to the flat caricatures of traditional social satire. It also differs from most of Molière's other works by focusing more on character development and nuances than on plot progression. The play, though not a commercial success in its time, survives as Molière's best-known work today.^{[citation needed]}

Because both Tartuffe and Don Juan, two of Molière's previous plays, had already been banned by the French government, Molière may have softened his ideas to make the play more socially acceptable. As a result, there is much ambiguity about whether the main character Alceste is intended as a hero for his uncompromising honesty, or as a quixotic fool. Molière has been the target of much criticism for The Misanthrope over the years. The French philosopher Jean-Jacques Rousseau claimed in his Letter to M. D'Alembert on Spectacles that it was Molière's best work, but hated that it made Alceste the butt of its humor. He believed the audience should support Alceste's high ideals rather than laugh at his misadventures.

Much to the horror of his friends and companions, Alceste rejects la politesse, the social conventions of the seventeenth-century French ruelles (later called salons in the 18th century). His refusal to "make nice" makes him tremendously unpopular and he laments his isolation in a world he sees as superficial and base, saying early in Act I, "... Mankind has grown so base, / I mean to break with the whole human race."

Despite his convictions, however, Alceste cannot help but love the coquette and playful Célimène, a consummate flirt whose wit and frivolity epitomize the courtly manners that Alceste despises. Though he constantly reprimands her, Célimène refuses to change, charging Alceste with being unfit for society because he hates humanity.

Despite his sour reputation as the misanthrope, Alceste does have women pining for him, particularly the prudish Arsinoé and the honest Éliante. Though he acknowledges their superior virtues, his heart still lies with Célimène. His deep feelings for her primarily serve to counter his negative expressions about mankind, since the fact that he has such feelings includes him amongst those he so fiercely criticizes.

When Alceste insults a sonnet written by the powerful noble Oronte, he is called to stand trial. Refusing to dole out false compliments, he is charged and humiliated and resolves on self-imposed exile.

Arsinoé, in trying to win his affection, shows him a love letter Célimène wrote to another suitor. He discovers that Célimène has been leading him on. She has written identical love letters to numerous suitors (including to Oronte) and broken her vow to favor him above all others. He gives her an ultimatum: he will forgive her and marry her if she runs away with him to exile. Célimène refuses, believing herself too young and beautiful to leave society and all her suitors behind. Philinte, for his part, becomes betrothed to Éliante. Alceste then decides to exile himself from society, and the play ends with Philinte and Éliante running off to convince him to return.