| Birth Date: | 17 June 1870 |
| Birth Place: | Suffield, Connecticut |
| Death Place: | Philadelphia, Pennsylvania |
| Nationality: | American |
| Fields: | Biology |
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| Spouse: | Margaret Reed Lewis |
Warren Harmon Lewis (June 17, 1870 – July 3, 1964) was an American embryologist and cell biologist. He was an elected member of the National Academy of Sciences and the American Philosophical Society. He served as president of the American Association of Anatomists and the International Society for Experimental Cytology, and held honorary memberships in the Royal Microscopical Society in London and Accademia Nazionale dei Lincei in Rome.[1] [2] [3]