Pierre Henri Puiseux (French: [pɥizø]; July 20, 1855 – September 28, 1928) was a French astronomer.
Born in Paris, son of Victor Puiseux, he was educated at the École Normale Supérieure before starting work as an astronomer at the Paris Observatory in 1885.
He worked on the aberration of light, asteroids, lunar dynamics and, in collaboration with Maurice Loewy, the ill-fated Carte du Ciel project. Puiseux created a photographic atlas of the Moon based on 6000 photographs taken by him and Loewy. In 1896 was he awarded the Lalande Prize of the French Academy of Sciences, and became a member of the academy in 1912.
The crater Puiseux on the Moon is named after him.