Moravian Serbia is the name used in historiography for the largest and most powerful state to emerge from the ruins of the Serbian Empire.

The state is created in 1373 and attains its largest extent in 1379 through the military and political activities of its first ruler, Prince Lazar Hrebeljanović.

The state comprises the basins of the Great Morava, West Morava, and South Morava Rivers.The name Moravian Serbia should not imply that the state was affiliated in any way with the region of Moravia in the present-day Czech Republic.

The adjective Moravian in this sense refers to the Morava Rivers which run through the Serbian entity.