|Uppu Aru Lagoon|
|Location||Jaffna District, Sri Lanka|
|Primary outflows||Jaffna Lagoon|
|Surface area||30 square kilometers (12 sq mi)|
|Max. depth||3 meters (9.8 ft)|
|Surface elevation||Sea level|
The lagoon has extensive mudflats and salt marshes. It is surrounded by mangroves, particularly Avicennia. The lagoon attracts a wide variety of water birds including American flamingoes, ducks, garganey, black-tailed godwit and other shorebirds.