The Alte River is a small river in the Portuguese region of the Algarve. The river along with the Algibre River, another tributary, becomes the Quarteira River after the two rivers conflux. The source of the river is a short distance east of the village of Alte and it runs for a distance of 11.6 kilometres (7.2 mi) to its confluence with the Algibre River near the village of Paderne.