- Irish, J. C. (John Carroll), 1843-8
- Irish, J. C. (John Carroll), 1843- author1
- Irvine, Matthew, approximately 1755-18271
- Irving, Peter, 1772-18381
- Irwin, Bernard John Dowling, 1830-19171
- Irwin, Bernard John Dowling, 1830-1917 author1
- Irwin, Bernard John Dowling, 1830-1917, author3
- Irwin, J. A. (John Arthur), 1853- author2
- Irys, José María, author2
- Isaacs, C. E. (Charles Edward), 1811-18604
- Isham, Asa B. (Asa Brainerd), 1844-1912, author1
- Ishiguro, Tadanori, 1845-1941, author1
- Ithaca (N.Y.). Board of Health, author.1
- Ives, Ansel W. (Ansel Wilmot), 1787-18381
- Ives, Charles L. (Charles Linnaeus), 1831-1879, author1
- Ives, Charles L., 1831-18791
- Ives, Eli, 1779-18611
- Ives, John, M.D1
- Ivy, Robert Henry, 1881-1974, author2
- Izaguirre, Ranulfo B., author1