Jules Marcou was born on April 20, 1824, in Salins, Jura, France.

He was a French geologist who traveled and worked in the U.S. He was educated at Besançon and at the Collège Saint Louis, Paris. After completing his studies, his stay in Switzerland led him to devote himself to natural science. He met Jules Thurmann (1804–1855), who introduced him to Louis Agassiz (1807-1873). In 1846, he was appointed Professor of Mineralogy at the Sorbonne and curator of fossil conchology at the Jardin des Plantes in 1847. He went to North America as a traveling geologist for the Jardin des Plantes. He joined Agassiz in Boston and accompanied him on several expeditions to Lake Superior, Lake Huron, and the Niagara region. In 1853, he was hired by the US government to serve as a geologist for the Pacific Railroad Survey along the 35th parallel. In 1855, he became Professor of Geology and Paleontology at the École Polytechnique of Zurich but relinquished the office in 1859. In 1861, he returned to the US and assisted Louis Agassiz in initiating the Museum of Comparative Zoology at Harvard College. He was in charge of its paleontological division from 1860 to 1864. He devoted himself to scientific research until 1875 when he again began service for the US government and accompanied the Wheeler Survey to Southern California. In 1867, Marcou was awarded the Grand Cross of the Legion of Honor. He wrote many articles and books on geological topics, e.g.; "Geological Map of the United States, and the British Provinces of North America" (1853), “Geological Map of the World” (1862), and "Life, Letters, and Works of Louis Agassiz" (1896).

In 1850, he married Jane Belknap (1818–1903). He died on April 17, 1898, in Cambridge, Massachusetts.