Jean Louis Rodolphe Agassiz was born on May 26, 1807, in Motier, Switzerland.

He was a Swiss-born American zoologist, geologist, and glaciologist, father of Alexander Agassiz, a scientist, and engineer. In 1829, he received a Doctor of Philosophy and Medical degree at the University of Erlangen and Munich, Germany, and was appointed professor of natural history at the University of Neuchâtel, Switzerland. In 1846, he immigrated to the United States. He became a professor of zoology and geology at Harvard University and the head of its Lawrence Scientific School. In 1859, he founded the Museum of Comparative Zoology and served as its president until his death. In 1863, he became one of the founding members of the National Academy of Sciences and was also appointed a regent of the Smithsonian Institution. He made vast institutional and scientific contributions to zoology, geology, and related areas, including writing multivolume research books. He contributed to ichthyological classification and to the study of geological history, including the founding of glaciology. An ancient glacial lake that formed in the Great Lakes region of North America, Lake Agassiz, is named after him, as are Mount Agassiz in California's Palisades, Mount Agassiz, in the Uinta Mountains, Utah, Agassiz Peak in Arizona, and in his native Switzerland, the Agassizhorn in the Bernese Alps.

In the 20th and 21st centuries, Agassiz's resistance to Darwinian evolution, belief in creationism, and the scientific racism implicit in his writings on human polygenism have tarnished his reputation and led to controversies over his legacy.

He died on December 14, 1873, in Cambridge, Massachusetts.

Mabel Simpkins Agassiz was the wife of George Russell Agassiz (1862-1951), a zoologist, astronomer, professor, and author, the son of Alexander Agassiz (1835-1910) and grandson of Louis Agassiz (1807-1873). The got married in 1902.