Elizabeth Cabot Agassiz (pseudonym, Actaea; Cary; December 5, 1822 – June 27, 1907) was an American educator, naturalist, writer, and the co-founder and first president of Radcliffe College. A researcher of natural history, she was an author and illustrator of natural history texts as well as a co-author of natural history texts with her husband, Louis Agassiz, and her stepson Alexander Agassiz. (who had graduated from Harvard University in 1811).

The Cary and Perkins families were from England and came to Massachusetts during the seventeenth century. Elizabeth Cary was the second of five daughters and seven children and was referred to as "Lizzie" by her immediate family and close friends. Because of her fragile health, she was tutored at home in Temple Place, Boston, which included the study of languages, drawing, music, and reading. She additionally received informal history lessons from Elizabeth Peabody.

Agassiz contributed to the founding of the coeducational Anderson School of Natural History. In 1869, she became one of the first women members of the American Philosophical Society (with Mary Fairfax Somerville and Maria Mitchell); she became a member on October 15.

Society for the Private Collegiate Instruction for Women

In 1879, Agassiz was one of seven female managing directors of the Society for the Private Collegiate Instruction for Women (Harvard Annex). This provided qualified women who intended to pursue an advancement in their education in Cambridge with the opportunity to have private tutoring from professors at Harvard College. and edited and published Louis Agassiz: His Life and Correspondence in 1885. A biography of Elizabeth Cabot Agassiz was later written by her sister, Emma F. Cary, and Lucy Allen Paton, published in the spring of 1917 with the assistance of the Council of Radcliffe College. Agassiz continued to devote time to her work and family. She continued to enjoy traveling, and in 1892, Agassiz ventured with family to the Pacific Coast, specifically California, for three months. She is buried in Mount Auburn Cemetery with her husband.