Acadagnostus is a genus of trilobite from the Middle Cambrian, with 7 species currently recognized. The type species A. acadicus has the widest distribution known from any peronopsid (with Peronopsis integer and P. scutalis) and has been found in North America, Greenland, England, Western Europe, Eastern Europe, Central Asia, the Altai Mountains, the Siberian shield, China, and Australia.