Helen Rex Keller (August 13, 1876 – January 21, 1967) was an American librarian and author of reference books.

[1][2] Her works included a two volume dictionary of dates.

[3] Keller edited and wrote the preface for the Library of the World's Best Literature, a 30-volume reference work with synopses of works of literature.

She also authored a Dictionary of Dates divided into two volumes for the "old world" and "new world",[5][6] and also authored the Readers's Digest of Books which provides summaries of about 1,500 books.

[1][7] Keller taught classes in library economy at Columbia University[8] and was the librarian for its journalism school.