While this book has many major and minor characters, these are among the most important:
- Toru Okada: The narrator and protagonist, Toru is a passive and often apathetic young man living in suburban Japan. He is Kumiko's husband and continually follows the orders or wishes of others. He had a job in a law firm, but currently unemployed, and he is the embodiment of passivity.
- Kumiko Okada: Kumiko is Toru's wife and, as the breadwinner of the couple, is the more autonomous of the two. She works in the publishing business.
- Noboru Wataya: Noboru is Kumiko's brother. He is presented as a mediagenic figure; the public loves him, but Toru cannot stand him. Noboru appears as an academic in the beginning, becomes a politician in the story, and has no apparent personal life. He is said to be hidden behind a façade — all style, and no substance. ("Noboru Wataya" is also the name Toru and Kumiko gave to their pet cat, whom Toru later renames Mackerel, like the fish; the character name also appeared in Family Affair, translated by Jay Rubin, of The Elephant Vanishes collection.)
- May Kasahara: May is a teenage girl who should be in school, but, by choice, is not. Toru and May carry on a fairly constant exchange throughout a good deal of the novel; when May is not present, she writes letters to him. Their conversations in person are often bizarre and revolve around death and the deterioration of human life. Even more bizarre is the cheerful and decidedly non-serious air with which these conversations take place.
- Lieutenant Mamiya: Mamiya was an officer during the Japanese occupation of Manchukuo, and meets Toru while carrying out the particulars of Mr. Honda's will. He has been emotionally scarred by witnessing the flaying of a superior officer and several nights spent in a dried-up well. He tells Toru his story both in person and in letters.
- Malta Kano: Malta Kano is a medium of sorts who changed her name to "Malta" after performing some kind of "austerities" on the island of Malta for some time. She is enlisted by Kumiko to help the Okadas find their missing cat.
- Creta Kano: Malta's younger sister and apprentice of sorts, she describes herself as a "prostitute of the mind." Disturbingly, for Toru, Creta bears a near-identical resemblance to Kumiko.
- Nutmeg Akasaka: Nutmeg first meets Toru as he sits on a bench watching people's faces every day in Shinjuku. The second time they meet she is attracted to the blue-black mark on his right cheek. She and Toru share a few strange coincidences: the wind-up bird in Toru's yard and the blue-black cheek mark appear in Nutmeg's World War II-related stories, and also Nutmeg's father and Lieutenant Mamiya (an acquaintance of Toru's) are linked by World War II. "Nutmeg Akasaka" is a pseudonym she chose for herself after insisting to Toru that her "real" name is irrelevant. Her real name is never mentioned in the novel.
- Cinnamon Akasaka: Cinnamon is Nutmeg's adult son who has not spoken since age 6. He communicates through a system of hand movements and mouthed words. Somehow, people who've just met him (who presumably have never lipread or used sign language) find him perfectly comprehensible. "Cinnamon," too, is a pseudonym created by Nutmeg.