- Koch, Theodore Wesley, 1871-1941, author2
- Kolbé, D. W.2
- Kolbé, D. W., author2
- Krohn, William O. (William Otterbein), 1868-1927, author2
- Küntscher, Gerhard, author2
- Lambert, T. S. (Thomas Scott), 1819-18972
- Lane, Levi Cooper, 1833-19022
- Larmont, M. (Martin)2
- Lazear, Jesse William, 1866-1900, author2
- Leaming, James R. (James Rosebrugh), 1820-1892, author2
- Lee, Charles A. (Charles Alfred), 1801-18722
- Lefevre, George, Sir, 1798-18462
- Lehmann, Karl Gotthelf, 1812-18632
- Leidy, Joseph, 1823-18912
- Lewis, Winslow, 1799-18752
- Library of Congress, compiler.2
- Lidell, John A.2
- Lindsay, A. A. (Arthur Adolphus), author2
- Lindsley, John Berrien, 1822-18972
- Lippe, Constantine.2