Pomorje or Primorje (literary meaning: by the sea, seaside, maritime or coastlands) is a term used in historical contexts to describe one of the two geographical divisions that constituted Serbia in the Middle Ages. It had parts of present-day Montenegro, Bosnia & Herzegovina, Croatia and Serbia.

It included most of modern Montenegro, the southern halves of Herzegovina and Dalmatia, while the other georgraphical division, the Zagorje (hinterlands or behind the hills) included most of modern Bosnia, the western half of the modern Kingdom of Serbia, and the northern portions of Montenegro and Herzegovina. Croatia lay to the north of Pomorje and Zagorje, covering all the country between the Pomorje and Sava.

The term was used in royal and religious titles; Serbian monarchs and their heirs (Uroš I, styled himself "King in Christ, God faithful, King of Serbia and Maritime Lands", and Patriarchs (Saint Sava III, "Archbishop of All Serbian and Maritime Lands")

The terms are first used in the De Administrando Imperio, a work by Byzantine Emperor Constantine VII (l. 905-959) dedicated to his son, Romanus II, as a domestic and foreign policy manual.