The Têt (; ) is the largest river in Pyrénées-Orientales, southwestern France. It is long. The Têt has its source at the foot of the Puig de la Cometa de l'Espagne in the Carlit massif in the eastern Pyrenees. It crosses the Pyrénées-Orientales département (Northern Catalonia) from West to East and ends in the Mediterranean Sea, near Perpignan ().
thumb|left|Puig de la Cometa de l'Espagne (2,763m). Below, on the right: the upper part of the Têt valley (here known as the vallée de la Grava).
A staircase of along the length of the valley has been studied in detail.
thumb|left|Llonat sits on a well-conserved vestige of an alluvial terrace of the Têt, about 100 metres above the river. It is thought that the terrace was formed just over half a million years ago. In the distance: the Pic du Canigou.
Tributaries include
- Riberole
- Carança
- Mantet
- Rotja
- Cady
- Castellane
- Lentillà
- Boulès
- Basse
Towns along the river
thumb|The Têt valley near Olette. The village of Canaveilles is beyond, on the right. Below, left, a [[Ligne de Cerdagne|"yellow train" is running on the line which descends the valley.]]
- Mont-Louis (Montlluís)
- Olette (Oleta)
- Villefranche-de-Conflent (Vilafranca de Conflent)
- Prades (Prada de Conflent)
- Perpignan (Perpinyà)
- Ille-sur-Têt (Illa)