Baltiysk, city and port, Kaliningrad oblast (province), northwestern Russia. It lies at the entrance to the tip of the narrow peninsula separating Frisches Lagoon from the Baltic Sea. Originally the German East Prussian town of Pillau (1686–1946), Baltiysk is connected by canal to Kaliningrad and serves as its outport. It also has good railway connections with Lithuania, Poland, and Belarus. Baltiysk has metalworking and light-engineering industries as well as ship-repairing facilities. Pop. (2006 est.) 33,255.