Dienvidsusēja
Dienvidsusēja near Gārsene
Location
Country	Latvia, Lithuania
Physical characteristics
Source
• location	near Subate
• elevation	81 m (266 ft)
Mouth	Nemunėlis (Mēmele)
• location	Sandariškai
• coordinates	56°24′11″N 24°55′27″E / 56.4030°N 24.9241°E / 56.4030; 24.9241
Length	114 km (71 mi)
Basin size	1,220.9 km2 (471.4 sq mi) (1,192.5 km2 (460.4 sq mi) within Latvia)
Discharge
• average	246 L/s (8.7 cu ft/s)
Basin features
Progression	Nemunėlis→ Lielupe→ Baltic Sea
Tributaries
• right	Zalvīte

The Dienvidsusēja (also known as Susēja or Suseja; Lithuanian: Susėja) is a river of Latvia and a right tributary of the river Mēmele. It flows for 114 kilometres. For 4.2 km, the river forms the border between Latvia and Lithuania. The river flows through Aknīste town, Nereta village and several smaller settlements.

• Zalvīte (36 km),
• Radžupe (21 km),
• Arālīte (21 km).

• List of rivers of Latvia