thumb|Achille Delesse
Achille Ernest Oscar Joseph Delesse (3 February 181724 March 1881) was a French geologist and mineralogist. He is credited for inventing the Delesse principle in stereology.
Education and career
Delesse was born at Metz. At the age of twenty he entered the École polytechnique, and subsequently went to the Ecole des Mines, where he was trained under the tutelage of Jean-Baptiste Élie de Beaumont and Ours-Pierre-Armand Petit-Dufrénoy. In 1845, he was appointed to the chair of mineralogy and geology at the University of Franche-Comté in Besançon. In 1850, he became the chair of geology at the Sorbonne in Paris; and in 1864, professor of agriculture at the Ecole des Mines.
Delesse died in Paris on 24 March 1881. In 1878, he became inspector-general of the Corps des mines.