Alexandre Dumas fils was born in Paris, France, the illegitimate child of Marie-Catherine Labay, a dressmaker, and novelist Alexandre Dumas. In 1831 his father legally recognized him and ensured the young Dumas received the best education possible at the Institution Goubaux and the Collége Bourbon. Laws at that time allowed Dumas Sr. to take the child away from his mother and her agony inspired Dumas fils to write about tragic female characters. In most all of his writings, he emphasized the moral purpose of literature and in his 1858 play, "The Natural Son," he espoused the theory that if someone brings an illegitimate child into the world, then they have an obligation to legitimize the child and marry the woman.
In addition to the stigma of illegitimacy, Dumas fils was part black, his father the mulatto descendant of a white French nobleman and a black Haitian girl. In the boarding schools, Dumas fils was constantly taunted by his classmates. These issues all profoundly influenced his thoughts, behaviour, and writing.
In 1844 Dumas fils moved to Saint-Germain-en-Laye to live with his father. There, he met Marie Duplessis, a young courtesan who would be the inspiration for his romantic novel, La dame aux camélias (The Lady of the Camillas). Adapted into a play, it was titled in English as Camille and is the basis for Verdi's 1853 opera, La Traviata.
In 1864, Alexandre Dumas fils married Nadeja Naryschkine, with whom he had a daughter. After her passing he married Henriette Régnier.
During his lifetime, Dumas fils wrote twelve other novels and several plays. In 1867 he published his semi-autobiographical novel, "L'affaire Clémenceau," considered by many to be one of his best works. In 1874, he was admitted to the Académie française and in 1894 he was awarded the Légion d'Honneur.
Alexandre Dumas fils died at Marly-le-Roi, Yvelines, on November 27, 1895 and was interred in the Cimetière de Montmartre, Paris, France.