Antoine Joseph Bernard Brunhes (3 July 1867 – 10 May 1910) was a French geophysicist known for his pioneering work in paleomagnetism, in particular, his 1906 discovery of geomagnetic reversal.

Brunhes was educated at the École Normale Supérieure in Paris, from which he graduated as an agrégé qualified in physics.

In November 1900, he was appointed as head of the Puy-de-Dôme Observatory, built on an extinct volcano in the Auvergne region of France, where he worked until his death in 1910.

It was during his time at the observatory that he made the crucial observation that led to his discovery of geomagnetic reversal.

In 1905, he found that rocks in an ancient lava flow at Pontfarin in the commune of Cézens (part of the Cantal département) were magnetised in a direction almost opposite to that of the present-day magnetic field.