Néel, who was born at Lyons in France, studied at the Ecole Normale Supérieure, later becoming professor of physics at the University of Strasbourg and subsequently at Grenoble. He became director of the Grenoble Polytechnic Institute in 1954 and director of the Center for Nuclear Studies there in 1956. He retired in 1976.

Most of his work was concerned with the magnetic properties of solids. About 1930 he suggested that a new form of magnetic behavior might exist – called antiferromagnetism. This is exhibited by such substances as manganese(II) oxide (MnO), in which the magnetic moments of the Mn atoms and O atoms are equal and parallel but in opposite directions. Above a certain temperature (the Néel temperature) this behavior stops. More generally, Néel pointed out (1947) that materials could also exist in which the magnetic moments were unequal – the phenomenon is called ferrimagnetism.

Néel also did considerable work on other magnetic properties, including an explanation of the weak magnetism of certain rocks that has made it possible to study the past history of the Earth's magnetic field. He was awarded the Nobel Prize for physics in 1970.