Southern Serbia (Serbian: Јужна Србија, romanized: Južna Srbija) or sometimes referred to as South Serbia, Southeastern Serbia, Southern Pomoravlje, South of Central Serbia, historically known as New Territories, is a historical and geographical region in Republic of Serbia which most often refers to the territories of Nišava, Toplica, Jablanica, Pčinja and Pirot Districts. This region occupies about 14,000 square kilometers and is home to about 877.000 people. More than a quarter of the population in the region lives in the city of Niš. People from Southern Serbia are commonly known as Southerners.
Southern Serbia is not an official subdivision of Serbia, nor are its borders precisely defined. The region is characterized by the South Morava river, which flows almost entirely through Southern Serbia and which has historically connected the peoples who lived in its basin. The region is defined by a common history and culture.