Jacob Nathaniel Blanck (November 10, 1906 – December 23, 1974) was an American bibliographer, editor, and children's writer.

Born in Boston, he attended local schools and briefly ran a bookshop before being hired to assist on a bibliography of American first editions.

[7] In the early 1940s, Blanck suggested to the Bibliographical Society of America that it sponsor a bibliography of American literature.

[9] The Lilly Endowment provided funding and Carroll A. Wilson, a book collector, was named chair of the project.

[15][16] Frederick M. Meek of the Massachusetts Historical Society pointed to his "hard work, incredible amount of knowledge, unusual memory and recall" combined with "a deep sensitive pride in what he did" which made him "the authority in his field – the field of American literature bibliography – culminating in BAL".