Cornelia Maria Clapp (March 17, 1849 - December 31, 1934) was an American ichthyologist and academic specializing in marine biology. She taught mathematics and zoology, and also created a manual of exercises for the school's gymnastics courses at Mount Holyoke after graduating in 1871. She continued her postgraduate studies at Louis Agassiz's Anderson School of Natural History in 1874. She later attended Syracuse University, earning a PhB degree in 1881 and a PhD in 1882. Beginning in 1888, she was affiliated with the Marine Biological Laboratory at Woods Hole, Massachusetts, where she conducted laboratory research and later became a lecturer and a trustee. Although she was primarily known as an educator and did not author many scientific research papers, she was named in 1906 as being among the 150 most prominent zoologists in the US by the journal American Man of Science. She died in 1934 at a the age of 85.