Octave Feuillet was born at Saint-Lô, Manche (Normandy). His father Jacques Feuillet was a prominent lawyer and Secretary-General of La Manche, but also a hypersensitive invalid. His mother died when he was an infant. Feuillet inherited some of his father's nervous excitability, though not to the same degree. He was sent to Lycée Louis-le Grand, in Paris, where he achieved high distinction, and was destined for the diplomatic service.

In 1840 he told his father that he planned to be a writer instead, and the elder Feuillet disowned his son. Octave Feuillet returned to Paris and lived as best he could by becoming a journalist. In company with Paul Bocage he wrote the plays Echec et mat, Palma ou la nuit de Vendredi saint, and La Vieillesse de Richelieu. His father forgave him three years later and granted him an allowance. Feuillet enjoyed a comfortable existence in Paris and published his first novels.

The health of the elder M. Feuillet declined further, and he summoned his son to leave Paris and attend to him at Saint-Lô. This was a great sacrifice, but Octave Feuillet obeyed. In 1851, he married his cousin Valérie Feuillet (née Dubois), who was also a writer. During his "exile" in Saint-Lô (rendered irksome by his father's mania for solitude and tyrannical temper), Feuillet produced some of his best work. His first definite success came in 1852, when he published the novel Bellah and produced the comedy La Crise. Both were reprinted from the Revue des deux mondes, where many of his later novels also appeared. Other acclaimed works are La Petite Comtesse (1857), Dalila (1857), and the popular Le Roman d'un jeune homme pauvre (1858).

Feuillet himself fell into a nervous state at Saint-Lô, but his wife and mother-in-law's devotion helped sustain him. In 1857, he finally returned to Paris to oversee the rehearsal of a play he had adapted from his novel Dalila. The following year, he did the same thing when Un jeune homme pauvre was rehearsing. Unfortunately, his father died at this time when he was away from home.

Feuillet and his family immediately moved to Paris and became a favorite at the court of the Second Empire. His pieces were performed at Compiègne before they were given to the public, and on one occasion the empress Eugénie played the part of Mme de Pons in Les Portraits de la Marquise.

Feuillet did not abandon the novel, and in 1862 he achieved a great success with Sibylle. His health, however, had by this time begun to decline, affected by the death of his eldest son. He left Paris for the quieter Normandy. The old chateau of the family had been sold, but he bought a house called Les Paillers in the suburbs of Saint-Lô, and there he lived, buried in his roses, for fifteen years.

He was elected to the French Academy in 1862, and in 1868 he was made librarian of Fontainebleau palace, where he had to reside for a month or two in each year. In 1867 he produced his masterpiece Monsieur de Camors, and in 1872 he wrote Julia de Tréc?ur. He spent his last years, after the sale of Les Paillers, in ceaseless wandering, due to his depression and ill health. He died in Paris on the 29th of December 1890. His last book was Honneur d'artiste (1890).

Feuillet holds a place midway between the romanticists and the realists. He is renowned for his "distinguished and lucid portraiture of life," depictions of female characters, analyses of characters' psychologies and feelings, and his excellent, reserved but witty prose style.