This thesis represents the first analytical overview of Catholic printing in the Dutch Republic over the course of the long seventeenth century (1566-1723). Roman Catholics made up a substantial proportion of the population of the Dutch Republic. Though they were barred from worshipping in public, holding office or accessing municipal funds, they maintained a remarkable degree of autonomy in practising their faith. Nowhere was this freedom better exercised than in the book trade, of which Catholic print made up a meaningful part. This project makes two primary and interconnected assertions. It argues that Catholic print was an independent and substantial genre, essential to the life of the Catholic community, and that Catholic books were valuable and popular commodities for both Reformed and Catholic owners in the Dutch Republic. Though extant scholarship and the work of digital bibliographies are both beginning to reveal the importance of this trade, neither have fully acknowledged its true scale and scope. This is due both to survival bias and the exclusion of certain types of print from consideration, not previously considered to be of significance. This project proposes an initial step towards an evaluation of the totality of the market by including new typologies of Catholic print and printed ephemera. It also argues that while Reformed censorship of Catholic books was a polite, rarely enforced fiction, Catholic censorship was a constant and direct concern for both Catholic book producers and readers. False imprints, obscuring the true sources of publications, played an important role in defusing tensions with both sets of authorities. This thesis also contends that future studies of the Catholic book trade need to look towards the margins. This includes the margins of bibliography such as lost books and ephemera, the physical borderlands of the Dutch Republic including the Generality Lands and the social margins, including the Catholic lay sisters called spiritual daughters. ; "I am grateful for the ...