He was born at Dieuze, in the Moselle département in the Lorraine region of France. In 1848 he entered the École Normale, taking second place in the annual competition for admission in which Hippolyte Taine came first. Among his college contemporaries, besides Taine, were Francisque Sarcey, Challemel-Lacour and Prevost-Paradol. Of them all, About was considered the most highly vitalized, exuberant, brilliant and "undisciplined". It is said that one of his schoolmasters told him "You will never be more than a little Voltaire," and About's career did tend toward Voltaire-style witty satire and commentaries on contemporary issues.

At the end of his college career, he joined the French school in Athens, but claimed that he had never intended to follow the professorial career for which the École Normale was a preparation, and in 1853 he returned to France and devoted himself to literature and journalism.

He made his name as an entertaining anti-clerical writer. The satirical Le roi des montagnes (The King of the Mountains) translated into English by Mary Louise Booth is the best-known of his novels. In Greece, About had noticed that there was a curious understanding between the brigands and police: brigandage was becoming almost a safe and respectable industry. About pushed this idea to invent the story of a brigand chief who converts his business into a registered joint stock company.

His book on Greece, La Grèce contemporaine (1855) was an immediate success. In Tolla (1855), About was charged with drawing too freely on an earlier Italian novel, Vittoria Savelli (1841). This aroused prejudice against him, and he was the object of numerous attacks. The Lettres d'un bon jeune homme, written to the Figaro under the signature of "Valentin de Quevilly", provoked more animosities. During the next few years, he wrote novels, stories, a play (which failed), a book-pamphlet on the Roman question, many pamphlets on other subjects of the day, innumerable newspaper articles, some art criticisms, rejoinders to the attacks of his enemies, and popular manuals of political economy, L'A B C du travailleur (1868), Le progrès (1864). His more serious novels include Madelon (1863), L'Infâme (1867), the three that form the trilogy of the Vieille Roche (1866), and Le roman d'un brave homme (1880) — a kind of counterblast to the view of the French workman presented in Zola's Assommoir. He is best remembered as a farceur, for the books Le nez d'un notaire (1862); Le roi des montagnes (1856); L'homme à l'oreille cassée (1862); Trente et quarante (1858); Le cas de M. Guérin (1862).

About's attitude towards the empire was friendly but critical. He greeted the liberal ministry of Émile Ollivier at the beginning of 1870 with delight, and welcomed the Franco-Prussian War. But as a result of the war he lost his beloved home in Alsace, which he had purchased in 1858 out of the fruits of his earlier literary successes. With the fall of the empire, he became a republican, and threw himself into battle against conservative reactionaries. From 1872 to about 1877, his paper, the XIX^eSiècle (19^th Century), became a power in the land. His political career, however, failed to advance further.

On 23 January 1884 he was elected a member of the Académie française, but died before taking his seat.