The Lordship of Prilep, also known as the Lordship of King Marko (Serbian: Област краља Марка), was one of the provinces of the Serbian Empire, centered around the city of Prilep and covering (mainly) the region of Pelagonia and surrounding areas in western parts of the present-day Republic of Macedonia. In the middle of 14th century, the region was held by lord Vukašin Mrnjavčević, who in 1365 became Serbian King and co-ruler of Serbian Emperor Stefan Uroš V (1355-1371). After king Vukašin died at the Battle of Maritsa in 1371, the region of Prilep was obtained by his son and designated successor (rex iunior) Marko Mrnjavčević, who took the title of Serbian King and chose the city as his main residence. King Marko ruled from Prilep until his death in the Battle of Rovine in 1395. By the end of the same year, the entire region of Prilep was conquered by Ottoman Turks.
Since 1334, the city of Prilep was under Serbian rule and the surrounding region was held by Serbian feudal lord Vukašin Mrnjavčević, who was crowned the king of the Serbs and Greeks in 1365 as the co-ruler of last Serbian emperor Stefan Uroš V. After the death of both Vukašin and Uroš in 1371, Vukašin's son Marko Mrnjavčević, who held the title "Youg King" (rex iunior), became the sole legal ruler of the Serbian Realm and took the title of Serbian King, but his power was contested by other Serbian feudal lords who gained control over other regions leaving Marko only with the areas in western Macedonia, centered in Prilep. King Marko remained effective ruler only in the region of Prilep, and was also nominaly recognized by some other feudal lords in surrounding areas. All of them, including King Marko, were forced to pay tribute to invading Ottoman Turks. Since he became vassal of Turkish Sultan, Marko Mrnjavčević was obligated to answer to sultans call in 1395 and take part in the Battle of Rovine where he was killed. Turks took the opportunity, and conquered the region of Prilep, adding its territory to the Sanjak of Ohrid.
Since Marko, who styled himself as Serbian King, did not reduce his title to Prilep or any other local town or region, historians have used various terms for his domain. In Serbian historiography, it is called simply: the Lordship of King Marko (Serbian: Област краља Марка) or the Domain of King Marko (Serbian: Држава краља Марка). In some other historiographies, it is sometimes called the Realm of Prilep (Macedonian and Bulgarian: Прилепско кралство).