In 1856 he left Lyon, where his schooldays had been mainly spent, and began his career as a schoolteacher at Alès, Gard, in the south of France.

The position proved to be intolerable and Daudet said later that for months after leaving Alès he would wake with horror, thinking he was still among his unruly pupils.

On 1 November 1857, he abandoned teaching and took refuge with his brother Ernest Daudet, three years his senior, who was trying, "and thereto soberly", to make a living as a journalist in Paris.

Alphonse took to writing, and his poems were collected into a small volume, Les Amoureuses (1858), which met with a fair reception.

He obtained employment on Le Figaro, then under Cartier de Villemessant's energetic editorship, wrote two or three plays, and began to be recognized in literary communities as possessing distinction and promise.

Henceforward his career was that of a successful man of letters, mainly spent writing novels: Le Nabab (1877), Les Rois en exil (1879), Numa Roumestan (1881), Sapho (1884), L'Immortel (1888), and writing for the stage: reminiscing in Trente ans de Paris (1887) and Souvenirs d'un homme de lettres (1888).

Daudet also wrote for children, including La Belle Nivernaise, the story of an old boat and her crew.

In 1867 Daudet married Julia Allard, author of Impressions de nature et d'art (1879), L'Enfance d'une Parisienne (1883), and some literary studies written under the pseudonym "Karl Steen".