Joseph Valentin Boussinesq (pronounced [ʒozɛf valɑ̃tɛ̃ businɛsk]; 13 March 1842 – 19 February 1929) was a French mathematician and physicist who made significant contributions to the theory of hydrodynamics, vibration, light, and heat.

John Scott Russell experimentally observed solitary waves in 1834 and reported it during the 1844 Meeting of the British Association for the advancement of science.

In 1871, Boussinesq published the first mathematical theory to support Russell's experimental observation, and in 1877 introduced the Korteweg–De Vries equation.

In 1876, Lord Rayleigh published his mathematical theory to support Russell's experimental observation.

In 1897, he published Théorie de l'écoulement tourbillonnant et tumultueux des liquides ("Theory of the swirling and agitated flow of liquids"), a work that greatly contributed to the study of turbulence and hydrodynamics.