Charles Frederick Hartt was born on August 23, 1840, in Wilmot, Annapolis, Nova Scotia.

He was a Canadian-American geologist, paleontologist, and naturalist who specialized in the geology of Brazil. In 1860, he graduated from Acadia College in Wolfville, Nova Scotia. In 1861, he started to work as a student assistant for Louis Agassiz at the Museum of Comparative Zoology, Harvard University. This work lasted until 1864 when he received an appointment on the geological survey of New Brunswick. In 1865, he accompanied Agassiz to Brazil in the Thayer Expedition. Hartt fell in love with Brazil and spent 15 months exploring the coastal regions from Bahia to Rio de Janeiro. The large zoological collections he made were later used to prepare his book “Geology and Physical Geography of Brazil” (1870). In 1868, he was elected Professor of Natural History at Vassar College and Head of the Department of Geology of Cornell University, Ithaca, New York. He participated in four expeditions to Brazil (the Morgan Expeditions) from 1870 to 1878. He collected a great deal of data about the land and the people, contributing to new knowledge about the flora, the fauna, minerals, geography, linguistics, and ethnography. He was an accomplished draftsman, illustrator, and musician. In his last voyage, he collected more than 500,000 specimens, which were donated to the National Museum of Rio de Janeiro, where he worked as the founder and director of the section of geology from 1866 to 1867. In 1875, the Geological Commission of the Empire of Brazil was organized with Hartt as its chief.

In 1868, he married Lucy Cornelia Lynde (1846–1912). He died on March 18, 1878, in Rio de Janeiro, Brazil, after contracting yellow fever. He is buried in Buffalo, New York.