Jean Daniélou S.J. (14 May 1905–20 May 1974) was a theologian, a historian and a member of the Académie Française.
Jean-Guenolé-Marie Daniélou was born at Neuilly-sur-Seine, son of Charles and Madeleine (née Clamorgan). His father was an anticlerical politician, several times minister, and his mother an educator and founder of institutions for women's education. His brother Alain (1907–1964) was a noted Indologist.His sister, Ménie Grégoire, was a well-known exponent of popular feminism.
Daniélou studied at the Sorbonne, and passed his agrégation in Grammar in 1927. He joined the Society of Jesus (Jesuits) in 1929, becoming an educator, initially at a boys' school in Poitiers. He subsequently studied theology at Lyon and was ordained in 1938.
During World War II, he served with the Armée de l'Air (Air Force) in 1939–1940. He was demobilised and returned to civilian life. He received his doctorate in theology in 1942 and was appointed chaplain to the ENSJF, the female section of the École Normale Supérieure, at Sèvres. It was at this time that he began his work on patristics, the study of the Fathers of the Church. He was one of the founders of the Sources Chrétiennes collection. In 1944 he was made Professor of Early Christian History at the Institut Catholique de Paris, and later became dean. In the 1950's, he produced several historical studies, including The Bible and the Liturgy (1956) and The Lord of History (1958), that provided a major impetus to the development of Covenantal Theology (Roman Catholic).
At the request of Pope John XXIII, he served as an expert to the Second Vatican Council and in 1969 was made a cardinal. He was elected to the Académie Française on 9 November 1972, to succeed Cardinal Eugène-Gabriel-Gervais-Laurent Tisserant.
His unexpected death in 1974, in the home of a prostitute, was very diversely interpreted. He died on the stairs of a brothel that he was visiting as part of his priestly duties. He used to provide pastoral care to poor people and women of Paris slums.
A number of his works on the early Church, abridged for a popular audience, remain in print.