Jean Nicolas Pierre Hachette (6 May 1769 – 16 January 1834), French mathematician, was born at Mézières, where his father was a bookseller.

While there he sent several papers, in which some questions of navigation were treated geometrically, to Gaspard Monge, at that time minister of marine, through whose influence he obtained an appointment in Paris.

Accompanying Guyton de Morveau in his expedition, earlier in the year, he was present at the battle of Fleurus, and entered Brussels with the French army.

The necessary royal assent was in 1823 refused to the election of Hachette to the Académie des Sciences, and it was not until 1831, after the July Revolution, that he obtained that honour.

It was left to him to develop the geometry of Monge, and to him also is due in great measure the rapid advancement which France made soon after the establishment of the École Polytechnique in the construction of machinery.