Isidore-Alexandre-Augustin Pils (1815–1875) was a French academic painter of religious and military subjects.
He was born in Paris, in 1831 became a student at the École des Beaux-Arts and studied under François-Édouard Picot. Pils's earlier paintings have religious themes. After experiences travelling with French troops through the Crimea, his themes took on military subject. He later produced many military scenes during the siege of Paris during the Franco-Prussian War of 1870. Pils was appointed professor of painting at the École des Beaux-Arts in 1863. In 1868 he was elected to seat #14 of the Académie des Beaux-Arts. Among his students were Adrien Moreau, Paul Adolphe Rajon, Julien Dupré, Luc-Olivier Merson, Ludovic Piette, Édouard Joseph Dantan and László Mednyánszky Henry-Lionel Brioux.
Pils died in Douarnenez and is buried in section 54 of Père Lachaise Cemetery.