Seybouse (Arabic: وادي سيبوس Oued Seybouse) is a river in northeastern Algeria, near the border with Tunisia. In Roman times, it was called the Ubus.
The river runs for a distance of about 225 km flowing through Guelma and Annaba Provinces. It starts in Medjez Amar, in the Tell Atlas north-west of Guelma Province. Its flows into the Mediterranean Sea at Seybouse (called Joannonville under French rule) to the south-east of the city of Annaba. Its mouth is just just north of Sidi Salem, the site of Hippo Regius where Saint Augustine lived in AD 391-430.
The Seybouse is used for irrigation of agricultural areas, but it is becoming polluted because of industrial activities.
(As of 1998; source: ANRH)
Coordinates: 36°52′01″N 7°46′18″E / 36.86694°N 7.77167°E