A gorilla who was captured from the West African wild when young and sent to an American zoo. After the zoo sold him to a menagerie, Walter Sokolow bought him and discovered he could communicate with him through his mind. Ishmael, learning he can talk telepathically with humans, begins teaching humans a subject he calls "captivity."
A middle-aged white American man who sought a teacher to show him how to save the world when he was younger, during the turbulent and idealistic 1960s. Now an adult, he finds an ad looking for a pupil who wants to save the world. Intrigued because his childhood question may be answered, but skeptical because he has never found answers in the past, he goes and finds Ishmael, who teaches him, as promised, about how to save the world. The narrator never reveals his name in Ishmael, though it is revealed in My Ishmael to be Alan Lomax.
- Walter Sokolow
A wealthy Jewish merchant who is mentioned only in Ishmael's back story but has died by the time of the main story. His family was killed in the Holocaust and he since migrated to the United States. While visiting a menagerie, he comes across a gorilla called Goliath (Ishmael's given alias at the menagerie). Sokolow buys Ishmael from the zoo and after he figures out that he and Ishmael can mentally speak to each other, the two study a vast array of subjects together. He is the one who gives the gorilla the new name of "Ishmael."
- Rachel Sokolow
Daughter of Walter Sokolow. She becomes Ishmael's benefactor after her father dies. She supports Ishmael for a span of time, but following her death and the subsequent end to Ishmael's financial support, Ishmael is forced to move into a situation that ultimately leads to his death.