Name: unnamed librarian
First Appearance: Action Comics (vol. 1) #19 (Dec. 1939): "Superman and the Purple Plague"
Number of Appearances: 1
Clark Kent and his ally, scientist Henry Travers, visited the library to read a rare book by De Fauvier about the Purple Plague of the Middle Ages. A similar plague was afflicting Metropolis and the two men hoped to find clues that would lead to a cure. The librarian told them they had to wait until another men brought the book back. Shortly the man and his nurse brought the book back to the librarian's desk. Unbeknownst to Kent, Travers, and the librarian, the other reader was actually Superman's arch-enemy the Ultra-Humanite, in disguise.
The librarian, a pretty black-haired woman wearing a pink dress, appeared in panels 3 and 4 of page 3 of the Superman story in Action Comics #19 (Dec. 1939). She had only one line: "You'll have to wait your turn! An old gentleman, who has been here frequently for it, is reading it now!"