The Jessie Hornsby papers date from 1876 to 1993 and measure 7.5 linear inches. Much of the collection consists of French-language materials. The bulk of the collection is composed of materials pertaining to Hornsby's research on the works of Marcel Proust and Georges Bernanos. It includes published works, lectures and drafts of manuscripts, and her PhD dissertation, "Le Tragique dans l'oeuvre de Georges Bernanos." Hornsby's notes on Proust consist of both her own observations on his body of work and typed passages quoted from other sources. Reviews of Hornsby's first book, which was adapted from her PhD dissertation and published in 1960, may be found within the collection. The book itself, Le Tragique dans l'ouevre de Georges Bernanos, is held by the University of Iowa Libraries.

The collection includes a few personal items, two unidentified black and white photographs, and Hornsby's curriculum vitae. Materials regarding her parents, Jessie and William Gillespie (including their original marriage certificate, which was issued in Canada, and a copy of William's birth certificate), may be found in the collection.