The North European (Caledonian), North American (Appalachian), and European–North African (Variscan) Paleozoic orogenic belts are a complex collage of accreted terranes and oceanic sutures defined by magmatism, deformation, and metamorphism. These orogenic belts do not represent isolated systems, detailed mapping and geochronological work has shown that subduction of oceanic crust in the Iapetan and Rheic systems was at least partly coeval. In addition, late Paleozoic overprinting of earlier orogenic features by tectonic and thermal events has obscured crucial geochronological, structural, and geochemical records. As a result, defining the continuity between individual terranes and oceanic sutures of various age in different areas remains a significant challenge. To address these issues, we invite colleagues across Earth Sciences to contribute to advancing our understanding of geodynamic processes and the large-scale organization of this complex orogenic collage. We particularly welcome detailed petrological, structural, geochronological, and multidisciplinary regional studies, as well as lithospheric- to mantle-scale modeling studies that target an integrated picture of Paleozoic re-arrangement of continents and ocean.