Voltaire was one of several Enlightenment figures (along with Montesquieu, John Locke and Jean-Jacques Rousseau) whose works and ideas influenced important thinkers of both the American and French Revolutions.

François Marie Arouet was born in Paris, the youngest of the five children (only three of which survived) of François Arouet (1650 – 1 January 1722), a notary who was a minor treasury official, and his wife, Marie Marguerite d'Aumart (ca. 1660 – 13 July 1701), from a noble family of the province of Poitou. Voltaire was educated by Jesuits at the Collège Louis-le-Grand (1704–1711), where he learned Latin and Greek; later in life he became fluent in Italian, Spanish and English.

By the time he left school, Voltaire had decided he wanted to be a writer, against the wishes of his father who wanted him to become a notary. Voltaire, pretending to work in Paris as an assistant to a notary, spent much of his time writing poetry. When his father found him out, he sent Voltaire to study law, this time in Caen (Normandy). Nevertheless, he continued to write, producing essays and historical studies. Voltaire's wit made him popular among some of the aristocratic families with whom he mixed. His father then obtained a job for him as a secretary to the French ambassador in the Netherlands, where Voltaire fell in love with a French Protestant refugee named Catherine Olympe Dunoyer. Their scandalous elopement was foiled by Voltaire's father and he was forced to return to France.[citation needed]

Most of Voltaire's early life revolved around Paris. From early on, Voltaire had trouble with the authorities for even mild critiques of the government and the Catholic Church. These activities were to result in numerous imprisonments and exiles. One satirical verse about the Régent thought to be by him led to his imprisonment in the Bastille for eleven months, until the real author came forward. While there, he wrote his debut play, Œdipe. Its success established his reputation.

The name "Voltaire", which the author adopted in 1718, is an anagram of "AROVET LI," the Latinized spelling of his surname, Arouet, and the initial letters of "le jeune" ("the younger"). The name also echoes in reverse order the syllables of the name of a family château in the Poitou region: "Airvault". The adoption of the name "Voltaire" following his incarceration at the Bastille is seen by many to mark Voltaire's formal separation from his family and his past.

Richard Holmes supports this derivation of the name, but adds that a writer such as Voltaire would have intended it to also convey its connotations of speed and daring. These come from associations with words such as "voltige" (acrobatics on a trapeze or horse), "volte-face" (a spinning about to face one's enemies), and "volatile" (originally, any winged creature). "Arouet" was not a noble name fit for his growing reputation, especially given that name's resonance with "à rouer" ("for thrashing") and "roué" (a "débauché").

In a letter to Jean-Baptiste Rousseau (not to be confused with Jean-Jacques) in March 1719, Voltaire concludes by asking that if Rousseau wishes to send him a return letter, he do so by addressing it to Monsieur de Voltaire. A post-scriptum explains: "J'ai été si malheureux sous le nom d'Arouet que j'en ai pris un autre surtout pour n'être plus confondu avec le poète Roi.", which translates as, "I was so unhappy under the name d'Arouet that I took another, primarily so that I would cease to be confused with the poet Roi." This probably refers to Adenes le Roi, and the 'oi' diphthong was then pronounced as modern French pronounces 'ai', so the similarity to 'Arouet' is clear, and thus, it could well have been part of his rationale. Indeed, Voltaire is additionally known to have used at least 178 separate pen names during his lifetime.

The aptitude for quick, perceptive, cutting and witty critical repartee for which Voltaire is known today made him highly unpopular with some of his contemporaries, including certain members of the French aristocracy. These sharp-tongued retorts were responsible for Voltaire's exile from France, during which he resided in Great Britain.

After Voltaire retorted to an insult given him by the young French nobleman Chevalier de Rohan in late 1725, the aristocratic Rohan family obtained a royal lettre de cachet, an irrevocable and often arbitrary penal decree signed by the French King (Louis XV, in the time of Voltaire) that was often bought by members of the wealthy nobility to dispose of undesirables. They then used this warrant to force Voltaire into imprisonment in the Bastille without holding a trial or giving him an opportunity to defend himself. Fearing an indefinite prison sentence, Voltaire suggested his own exile to England as an alternative punishment, an idea the French authorities accepted. This incident marked the beginning of Voltaire's attempts to improve the French judicial system.

Voltaire's exile in Great Britain lasted nearly three years, and his experiences there greatly influenced many of his ideas. The young man was impressed by Britain's constitutional monarchy in contrast to the French absolute monarchy, as well as the country's relative support of the freedoms of speech and religion. He was also influenced by several of the neoclassical writers of the age, and developed an interest in earlier English literature, especially the works of Shakespeare, still little known in continental Europe at the time. Despite pointing out his deviations from neoclassical standards, Voltaire saw Shakespeare as an example French writers might look up to, since drama in France, despite being more polished, lacked on-stage action. Later, however, as Shakespeare's influence was being increasingly felt in France, Voltaire would endeavour to set a contrary example with his own plays, decrying what he considered Shakespeare's barbarities.