Willem (Wilhelm, Guglielmo) Seiffert (fl. 1850-1866) was a German-born mapmaker and draftsman working in Italy in the mid-19th century. We know virtually nothing about this mapmaker, apart from several publishers with whom he partnered: Pellegrini in Torino, Prosperini in Padua, and the printers Kier and Fontana in Venice. In addition to a map of the Lagoon of Venice, and plans of Venice, Verona, and Belluno, he also appears to have produced an 1855 Italian manual of calligraphy. It is probable that he numbers among the many German printers and mapmakers who fled Germany after the 1848 revolution; while many of these made their way to the United States, it is not unlikely that some would have been able to establish themselves elsewhere in Europe.