- Hoag, Ernest Bryant, 1868-1924, author3
- Hoffman, Mabel E., author1
- Hoffman, U. J. (Urias John), 1855- author1
- Hogan, Louise E. (Louise Eleanor), 1855-1929, author1
- Hollingworth, Harry L. (Harry Levi), 1880-1956, author1
- Holmes, Samuel J. (Samuel Jackson), 1868-1964, author1
- Howe, Paul E., author1
- Huddleson, Mary Pascoe, 1889-1966, author1
- Huebner, S. S. (Solomon Stephen), 1882-1964, author1
- Humphreys, F. (Frederick), 1816-1900, author1
- Hutton, R. M. (Ruth Marjorie), 1892- compiler1
- Illinois State Water Survey, author, issuing body.1
- Illinois. Department of Public Health, author.1
- Ivy, Robert Henry, 1881-1974, author2
- Jaches, Leopold, 1873- author1
- Jackson, David P. (David Prentice), 1851- author1
- Jacobs, Philip P. (Philip Peter), 1879-1940, author1
- Jelliffe, Smith Ely, 1866-1945 author1
- Jenner, Edward, 1749-1823, author1
- Jennings, Hazel L., author1