Jean Becquerel (5 February 1878 – 4 July 1953) was a French physicist, and son of Antoine-Henri Becquerel. He worked on the optical and magnetic properties of crystals, discovering the rotation of the plane of polarisation by a magnetic field. He also published a textbook on relativity. In 1909, he became the fourth in his family to occupy the physics chair at the Muséum National d'Histoire Naturelle, following in the footsteps of his father, his grandfather A. E. Becquerel and his great-grandfather Antoine César Becquerel.
- Principe de Relativité et la Théorie de la Gravitation, Lectures given in 1921 and 1922 at the École Polytechnique and the Muséum d'Histoire Naturelle in Paris, Gauthier-Villars & Co. 1922