Ille-sur-Têt is a commune in the Pyrénées-Orientales département in southern France.

Its inhabitants are called Illois.

The commune is situated in the Ribéral region along the route nationale 116 and is crossed by the Têt River (in the north), as well as by its tributary, the Boulès (in the south). It is one of the gateways to the Fenouillèdes region (towards Montalba-le-Château or Bálesta).