Jérôme Franel (1859–1939) was a Swiss mathematician who specialised in analytic number theory.

He is mainly known through a 1924 paper,[1] in which he establishes the equivalence of the Riemann hypothesis to a statement on the size of the discrepancy in the Farey sequences, and which is directly followed (in the same journal) by a development on the same subject by Edmund Landau.

On 1 April 1886, then only 26 years old, he was appointed to the Chair of Mathematics in the French language at the Politechnikum in Zürich by the Federal Council of Switzerland.

In 1896 he was a member of the organizing committee of the first International Congress of Mathematicians, which took place in Zürich in 1897.

Under his presidency (1905–1909) the school was entirely restructured, and it was probably through his insistence (in particular, through a 1907 speech) that the Polytechnikum finally obtained (in 1908) the right to award a doctoral degree like the university did.