Charles Otis Whitman (December 6, 1842 – December 14, 1910) was an American zoologist, who was influential to the founding of classical ethology (study of animal behavior). In 1888, he was the founding director of the Marine Biological Laboratory. A dedicated educator who preferred to teach a few research students at a time, he made major contributions in the areas of evolution and embryology of worms, comparative anatomy, heredity, and animal behaviour. He was known as the "Father of Zoology" in Japan.