The geodynamics of Southeast Asia presents a set of processes both at the Earth's surface and deep in the Earth's interior that have shaped the evolution of our planet since the onset of plate tectonics. These processes include rifting at continental margins and marginal basins, long-lived to short-lived ocean subduction, arc and plume-related magmatism, collisional mountain building, and arc docking. Some of these processes are still ongoing or were active in the Cenozoic, which allows us to study those in great detail. Main unknowns on the geodynamics of SE Asia include questions on the reconstruction of the proto-South China Sea plate, paleo-Pacific subduction, and proto-Philippines Sea plate as well as the connection with the Tethyan realm to the south, the collision of Australian-derived fragments in eastern Indonesia and associated extension processes. To address these issues, we welcome contributions from all disciplines of the earth sciences focused on the geodynamics of Southeast Asia: field-based geology, geochronology, and geochemistry on detrital minerals and magmas, seismology, geodynamic thermal-mechanical modeling, plate kinematic and tectonic reconstructions.