Camille Jordan (January 5 1838 - January 22 1921) was a French mathematician, known both for his foundational work in group theory and for his influential Cours d'analyse. He was born in Lyons and educated at the Ecole Polytechnique. He was an engineer by profession; later in life he taught at the Ecole Polytechnique and the College de France; where he had a reputation for eccentric choices of notation.

He is remembered now by name in a number of foundational results:

In fact the work of Jordan did much to bring Galois theory into the mainstream. He also investigated the Mathieu groups, the first examples of sporadic groups. His Traité des substitutions, on permutation groups, was published in 1870.