Jens Christian Bay (October 12, 1871 – April 11, 1962[1][2]) was a Danish American writer and librarian.

[3][4] Bay was recognized as an authority on many subjects, including rare books, but was particularly interested in botany, English literature, and the history of the American Midwest.

He was a long-time friend of Young E. Allison, an author and newspaper editor of Louisville, Kentucky.

Bay and Allison shared a variety of interests, including the history of Kentucky, Stephen Foster, James Whitcomb Riley, Robert Louis Stevenson, and Charles Dickens.

Bay was also interested in the literature of his native Denmark, and was knighted by King Frederik IX in 1947.