Karlobag is a seaside municipality on the Adriatic coast in Croatia, located underneath the Velebit mountains overlooking the island of Pag, west of Gospić and south of Senj.

The Velebit mountains rising above Karlobag have been declared the a world biosphere reserve, currently the only one in Croatia.

[5] During migration period Vegia collapsed, but in the 7th century the Croats built a new settlement to the west of the Roman town, called Skrisa (Opidum Scrissi) which was later known as Bag, the seat of the noble Tugomirić family, then of Gusić-Kurjaković and Mogorović-Disislavić families.

Another Habsburg ruler (also called Karl) was responsible for Karlobag's further development, the last male member of the family and father of Maria Theresa, Charles VI.

His grandson Joseph II joined Karlobag to the "Vojna Krajina" in 1776 and in 1786 built another road over Velebit.

Until 1918, Karlobag (named Carlobago before 1850, later Karlopago) was part of the (Kingdom of Croatia-Slavonia after the compromise of 1867), in the Croatian Military Frontier, Likaner Regiment N°I.