In 1631, Jean Poquelin purchased from the court of Louis XIII the posts of "valet de chambre ordinaire et tapissier du Roi" ("valet of the King's chamber and keeper of carpets and upholstery"). His son assumed the same posts in 1641. The title required only three months' work and an initial cost of 1,200 livres; the title paid 300 livres a year and provided a number of lucrative contracts. Poquelin also studied as a provincial Lawyer some time around 1642, probably in Orléans, but it is not documented that he ever qualified. So far he had followed his father's plans, which had served him well; he had mingled with nobility at the Collège de Clermont and seemed destined for a career in office.

In June 1643, when Molière was 21, he decided to abandon his social class and pursue a career on the stage. Taking leave of his father, he joined the Actress Madeleine Béjart, with whom he had crossed paths before, and founded the Illustre Théâtre with 630 livres. They were later joined by Madeleine's brother and sister.

The new theatre troupe went bankrupt in 1645. Molière had become head of the troupe, due in part, perhaps, to his acting prowess and his legal training. However, the troupe had acquired large debts, mostly for the rent of the theatre (a court for jeu de paume), for which they owed 2000 livres. Historians differ as to whether his father or the lover of a member of his troupe paid his debts; either way, after a 24-hour stint in prison he returned to the acting circuit. It was at this time that he began to use the pseudonym Molière, possibly inspired by a small village of the same name in the Midi near Le Vigan. It was also likely that he changed his name to spare his father the shame of having an actor in the family (actors, although no longer vilified by the state under Louis XIV, were still not allowed to be buried in sacred ground).

Les Précieuses Ridicules was the first of Molière's many attempts to satirize certain societal mannerisms and affectations then Common in France. It is widely accepted that the plot was based on Samuel Chappuzeau's Le Cercle des Femmes of 1656. He primarily mocks the Académie Française, a group created by Richelieu under a royal patent to establish the rules of the fledgling French theater. The Académie preached unity of time, action, and styles of verse. Molière is often associated with the claim that comedy castigat ridendo mores or "criticises customs through humour" (a phrase in fact coined by his contemporary Jean de Santeuil and sometimes mistaken for a classical Latin proverb).

Molière was forced to reach Paris in stages, staying outside for a few weeks in order to promote himself with society gentlemen and allow his reputation to feed in to Paris. Molière reached Paris in 1658 and performed in front of the King at the Louvre (then for rent as a theatre) in Corneille's tragedy Nicomède and in the farce Le Docteur Amoureux with some success. He was awarded the title of Troupe de Monsieur (Monsieur being the honorific for the king's brother Philippe I, Duke of Orléans). With the help of Monsieur, his company was allowed to share the theatre in the large hall of the Petit-Bourbon with the famous Italian Commedia dell'arte company of Tiberio Fiorillo, famous for his character of Scaramouche. (The two companies performed in the theatre on different nights.) The premiere of Molière's Les Précieuses Ridicules (The Affected Young Ladies) took place at the Petit-Bourbon on 18 November 1659.

Les Précieuses Ridicules won Molière the attention and the criticism of many, but it was not a popular success. He then asked Fiorillo to teach him the techniques of Commedia dell'arte. His 1660 play Sganarelle, ou Le Cocu imaginaire (The Imaginary Cuckold) seems to be a tribute both to Commedia dell'arte and to his Teacher. Its theme of marital relationships dramatizes Molière's pessimistic views on the falsity inherent in human relationships. This view is also evident in his later works, and was a source of inspiration for many later authors, including (in a different field and with different effect) Luigi Pirandello. It describes a kind of round dance where two couples believe that each of their partners has been betrayed by the other's and is the first in Molière's 'Jealousy series' which includes Dom Garcie de Navarre, L'École des maris and L'École des femmes.

In 1661, Molière introduced the comédies-ballets in conjunction with Les Fâcheux. These ballets were a transitional form of dance performance between the court ballets of Louis XIV and the art of professional theatre which was developing in the advent of the use of the proscenium stage. The comédies-ballets developed accidentally when Molière was enlisted to mount both a play and a ballet in the honor of Louis XIV and found that he did not have a big enough cast to meet these demands. Molière therefore decided to combine the ballet and the play so that the his goal could be met while the performers catch their breath and change costume. The risky move paid off and Molière was asked to produce twelve more comédies-ballets before his death. During the comédies-ballets, Molière collaborated with Pierre Beauchamp. Beauchamp codified the five balletic positions of the feet and arms and was partly responsible for the creation of the Beauchamp-Feuillet dance notation. Molière also collaborated with Jean-Baptiste Lully. Lully was a Dancer, Choreographer, and Composer, whose dominant reign at the Paris Opéra lasted fifteen years. Under his command, ballet and opera rightly became professional arts unto themselves. The comédies-ballets closely integrated dance with music and the action of the play and the style of continuity distinctly separated these performances from the court ballets of the time; additionally, the comédies-ballets demanded that both the Dancers and the actors play an important role in advancing the story. Similar to the court ballets, both professionally trained Dancers and courtiers socialized together at the comédies-ballets - Louis XIV even played the part of an Egyptian in Molière's Le Mariage forcé (1664) and also appeared as Neptune and Apollo in his retirement performance of Les Amants magnifiques (1670).

On 20 February 1662 Molière married Armande Béjart, whom he believed to be the sister of Madeleine. (She may instead have been her illegitimate daughter with the Duke of Modena.) The same year he premiered L'École des femmes (The School for Wives), subsequently regarded as a masterpiece. It poked fun at the limited education that was given to daughters of rich families, and reflected Molière's own marriage. Both this work and his marriage attracted much criticism. The play sparked the protest called the "Quarrel of L'École des femmes". On the artistic side he responded with two lesser-known works: La Critique de "L'École des femmes", in which he imagined the spectators of his previous work attending it. The piece mocks the people who had criticised L'École des femmes by showing them at dinner after watching the play; it addresses all the criticism raised about the piece by presenting the critics' arguments and then dismissing them. This was the so-called Guerre comique (War of Comedy), in which the opposite side was taken by Writers like Donneau de Visé, Edmé Boursault, and Montfleury.

Tartuffe, ou L'Imposteur was also performed at Versailles, in 1664, and created the greatest scandal of Molière's artistic career. Its depiction of the hypocrisy of the dominant classes was taken as an outrage and violently contested. It also aroused the wrath of the Jansenists and the play was banned.

In 1666, Le Misanthrope was produced. It is now widely regarded as Molière's most refined masterpiece, the one with the highest moral content, but it was little appreciated at its time. It caused the "conversion" of Donneau de Visé, who became fond of his theatre. But it was a commercial flop, forcing Molière to immediately write Le médecin malgré lui (The Doctor Despite Himself), a satire against the official sciences. This was a success despite a moral treatise by the Prince of Conti, criticizing the theater in general and Molière's in particular. In several of his plays, Molière depicted the Physicians of his day as pompous individuals who speak (poor) Latin to impress others with false erudition, and know only clysters and bleedings as (ineffective) remedies.

After the Mélicerte and the Pastorale comique, he tried again to perform a revised Tartuffe in 1667, this time with the name of Panulphe or L'Imposteur. As soon as the King left Paris for a tour, Lamoignon and the archbishop banned the play. The King finally imposed respect for Tartuffe a few years later, after he had gained more power over the clergy.

Molière, now ill, wrote less. Le Sicilien ou L'Amour peintre was written for festivities at the castle of Saint-Germain-en-Laye, and was followed in 1668 by Amphitryon, inspired both by Plautus' work of the same name and Jean Rotrou's successful reconfiguration of the drama. With some conjecture, Molière's play can be seen to allude to the love affairs of Louis XIV, then king of France. George Dandin, ou Le mari confondu (The Confounded Husband) was little appreciated, but success returned with L'Avare (The Miser), now very well known.

Les Femmes savantes (The Learned Ladies) of 1672 is considered another of Molière's masterpieces. It was born from the termination of the legal use of music in theater, since Lully had patented the opera in France (and taken most of the best available Singers for his own performances), so Molière had to go back to his traditional genre. It was a great success, and it led to his last work (see below), which is still held in high esteem.

Molière's works were translated into English prose by John Ozell in 1714, but the first complete version in English, by Baker and Miller in 1739, remained "influential" and was long reprinted. The first to offer full translations of Molière's verse plays such as Tartuffe into English verse was Curtis Hidden Page, who produced blank verse versions of three of the plays in his 1908 translation. Since then, notable translations have been made by Richard Wilbur, Donald M. Frame, and many others.

In 1792 his remains were brought to the museum of French monuments and in 1817 transferred to Père Lachaise Cemetery in Paris, close to those of La Fontaine.

Russian Writer Mikhail Bulgakov wrote a semi-fictitious biography-tribute to Molière, titled Life of Mr. de Molière. Written 1932–1933, first published 1962.

In his memoir A Terrible Liar, actor Hume Cronyn writes that, in 1962, celebrated actor Laurence Olivier criticized Molière in a conversation with him. According to Cronyn, he mentioned to Olivier that he (Cronyn) was about to play the title role in The Miser, and that Olivier then responded, "Molière? Funny as a baby's open grave." Cronyn comments on the incident: "You may imagine how that made me feel. Fortunately, he was dead wrong."

The French 1978 film simply titled Molière directed by Ariane Mnouchkine and starring Philippe Caubère presents his complete biography. It was in competition for the Palme d'Or at Cannes in 1978.

He is portrayed among other Writers in The Blasphemers' Banquet (1989).

The 2000 film Le Roi Danse (The King Dances), in which Molière is played by Tchéky Karyo, shows his collaborations with Jean-Baptiste Lully, as well as his illness and on-stage death. The 2007 French film Molière was more loosely based on the life of Molière, starring Romain Duris, Fabrice Luchini and Ludivine Sagnier.

Through the patronage of aristocrats including Philippe I, Duke of Orléans—the brother of Louis XIV—Molière procured a command performance before the King at the Louvre. Performing a classic play by Pierre Corneille and a farce of his own, The Doctor in Love, Molière was granted the use of salle du Petit-Bourbon near the Louvre, a spacious room appointed for theatrical performances. Later, Molière was granted the use of the theatre in the Palais-Royal. In both locations he found success among Parisians with plays such as The Affected Ladies, The School for Husbands and The School for Wives. This royal favour brought a royal pension to his troupe and the title Troupe du Roi ("The King's Troupe"). Molière continued as the official author of court entertainments.

Though conventional thinkers, religious Leaders, and medical professionals in Molière's time criticised his work, their ideas did not really diminish his widespread success with the public. Other playwrights and companies began to emulate his dramatic style in England and in France. Molière's works continued to garner positive feedback in 18th-century England, but they were not so warmly welcomed in France at this time. However, during the French Restoration of the 19th century, Molière's comedies became popular with both the French public and the critics. Romanticists admired his plays for the unconventional individualism they portrayed. 20th-century scholars have carried on this interest in Molière and his plays and have continued to study a wide array of issues relating to this Playwright. Many critics now are shifting their attention from the philosophical, religious, and moral implications in his comedies to the more objective study of his comic technique.