Remains of Halisaurus sternbergi (Wiman, 1920) from the latest Early Campanian (sensu germanico) of the Kristianstad Basin, southern Sweden, represent the first record of this species outside of the USA. The material comprises numerous marginal tooth-crowns, a premaxilla, an incomplete pterygoid, and vertebrae. The Kristianstad Basin population of H. sternbergi was probably derived from individuals that migrated from the Mississippi Embayment in North America sometime during the Early Campanian. Even though H. sternbergi thrived in great numbers in the coastal waters of the southern part of the Baltic Shield during the latest Early Campanian, the population appears to have been short-lived. Available data indicate that H. sternbergi, along with several other species of mosasaurs, vanished from the region following an intercontinental mosasaur extinction event, or a series of events, near the Early/Late Campanian boundary.