Cornelia Maria Clapp (born March 17, 1849, Montague, Mass., U.S.—died Dec. 31, 1934, Mount Dora, Fla.) was an American zoologist and educator whose influence as a teacher was great and enduring in a period when the world of science was just opening to women.
Clapp graduated from Mount Holyoke Female Seminary in 1871, and after a year of teaching elsewhere she returned to Mount Holyoke as an instructor in mathematics. Later she also taught gymnastics. Her budding interest in natural history was encouraged when, in 1874, she was selected to attend the summer Anderson School of Natural History conducted by Louis Agassiz at Penikese Island in Buzzards Bay, Massachusetts. Soon Clapp was teaching zoology at Mount Holyoke, where she developed a vivid laboratory method of instruction that proved highly effective. She continued her own education on numerous field trips and in formal studies at the Massachusetts Institute of Technology in Cambridge, at Williams College in Williamstown, Massachusetts, at Syracuse (New York) University, where she received a Ph.D. degree in 1889, and at the University of Chicago, where she took a second doctorate in 1896.
In 1896, eight years after Mount Holyoke became a college, Clapp helped organize the department of zoology, and in 1904 she was named professor of zoology. From its opening in 1888 she was involved in the work of the Marine Biological Laboratory at Woods Hole, Massachusetts. She carried on research there, primarily in the field of embryology, and served as librarian in 1893–1907 and as a trustee in 1897–1901 and again in 1910. She retired as professor emeritus from Mount Holyoke in 1916 but continued for several years to summer at Woods Hole. She published little during her career, her major influence being to extend scientific knowledge and opportunity to women through education. In 1923 Clapp Hall, housing the science departments and laboratories, was dedicated at Mount Holyoke.