We report the first finding of the grasshopper Aiolopus thalassinus (Fabricius, 1781) inthe Nordic countries. Two migrating individuals were attracted to light at a known hotspotof migrating moths near the southernmost tip of Gotland in the Baltic Sea, 8th of August2020. End of September hundreds of individuals had made landfall in a bay not far from thefirst locality. The mass occurrence followed after days of easterly or southeasterly winds,a strengthened high pressure over Russia, and an early morning with low-lying clouds.Aiolopus thalassinus is a long-winged grasshopper with strong flight capacity and a widedistribution across the Old World. It also shares some of the density-dependent behavioraland physiological characteristics of the migratory locusts. In Europe the northern continuousdistribution limit stretches through south Germany and middle Poland. The findings onGotland follow the first record in Lithuania, 2019, and a recent trend of expanding rangein south Germany which indicates a species expanding its distribution due to a changingclimate. The findings also show that this is a species capable of swarm migration and crossinga minimum of 170 km of open sea when winds are favorable.