Adah Elizabeth Verder (June 18, 1900 − August 28, 1997) was an American medical bacteriologist and science administrator. She was a researcher in the National Institute of Allergy and Infectious Diseases' (NIAID) intramural research program specialized in gastrointestinal flora and staphylococci, pseudomonas, and pleuropneumonia organisms. Verder later served as chief of the bacteriology and mycology branch in the extramural division of NIAID. She was a fellow of several societies including the American Association for the Advancement of Science, American Public Health Association, American Academy of Microbiology, and the New York Academy of Sciences.