The site of today's Zelenogradsk was originally an Old Prussian fishing village, in the proximity of Kaup, a Prussian town on the coast of the Baltic Sea in the Viking era. The area became controlled by the Teutonic Knights and settled with Germans. The German name Cranz, originally Cranzkuhren, derives from the Old Prussian word krantas, meaning "the coast". For most of its history it remained a small village in East Prussia.
During the 19th century, the village became the primary seaside resort for the Kingdom of Prussia on the East Prussian coastline, especially after the construction of a railway line connecting the village with K�nigsberg (now Kaliningrad) in 1885. From 1816�1895 it was known as das k�nigliche Bad, or "the royal bath/resort". Despite the increase of tourists, the fishing industry remained strong; smoked flounder was a regional delicacy. Although it had over 6,000 inhabitants before the beginning of World War II, it did not have town privileges.
The area was overrun by the Soviet Red Army during World War II and annexed to Russia, although it suffered minimally through warfare. The German population fled during the evacuation of East Prussia or was subsequently expelled by force. The village, renamed from Cranz to Zelenogradsk or "Green City" in Russian, received a civic charter after 1945.
The tourism industry was neglected during the Cold War and Zelenogradsk's tourism primacy was relinquished to nearby Svetlogorsk (formerly Rauschen). This policy changed in recent years. Zelenogradsk is becoming more popular with Russian vacationers, and many rich Muscovitesown private houses in the area
