Wilfrid Voynich was a Polish revolutionary, antiquarian and bibliophile. Voynich operated one of the largest rare book businesses in the world. He is remembered as the eponym of the Voynich manuscript.

The Voynich manuscript is an illustrated codex, hand-written in an unknown script referred to as 'Voynichese.' The vellum on which it is written has been carbon-dated to the early 15th century (1404–1438). Stylistic analysis has indicated the manuscript may have been composed in Italy during the Italian Renaissance. While the origins, authorship, and purpose of the manuscript are still debated, hypotheses range from a script for a natural language or constructed language, an unread code, cypher, or other form of cryptography, or perhaps a hoax, reference work, or work of fiction currently lacking the translation(s) and context needed to both properly entertain or eliminate any of these possibilities.