Belgian author, of French nationality by marriage, one of the leading contemporary exponents of the traditional French novel of psychological love analysis. Her father was a statesman and her mother, Suzanne Lilar (Lilar, Suzanne), an author and a critic.

At age 19 Françoise Lilar won unanimous critical approval with her novel Le Rempart des béguines (1951; The Illusionist, also published as Into the Labyrinth and The Loving and the Daring), the story of an affair between a girl and her father's mistress, described with clinical detachment in a sober, classical prose. A sequel, La Chambre rouge (1953; The Red Room), and a book of short stories, Cordélia (1956; Cordelia and Other Short Stories), continued in the detached manner of her first novel, but her style changed with Les Mensonges (1956; House of Lies), which told of the struggle between a dying businessman and his illegitimate daughter, who remains true to her mother.

In L'Empire Céleste (1958; Café Céleste) and Les Signes et les prodiges (1966; Signs and Wonders), she pursued the search for a truth hidden beneath a proliferation of human activities. She turned to the historical novel with Les Personnages (1960; The Favourite), about the intrigues of Cardinal de Richelieu with regard to the love life of King Louis XIII, and with Marie Mancini le premier amour de Louis XIV (1964; The Uncompromising Heart: A Life of Marie Mancini, Louis XIV's First Love). Bluntly candid about herself, Mallet-Joris revealed much of her personal life, her inner conflicts and her religious quests—she became a Roman Catholic convert—in her autobiographical writings, Lettre à moi-même (1963; A Letter to Myself) and La Maison de papier (1970; The Paper House). Among her later novels are Le Jeu de souterrain (1973; The Underground Game), Allegra (1976), Dickie-Roi (1979), and Un Chagrin d'amour et d'ailleurs (1981; “A Sorrow of Love and More Besides”). She also wrote a biography of Jeanne Guyon (1978), the 17th-century French mystic. Her writings reveal a richness and abundance of detail and colour that is reminiscent of those of Honoré de Balzac or of the paintings of the Flemish masters. Abandoning the Belgian roots evident in her early work, Mallet-Joris opted for a thoroughly Parisian literary career.