The Salso (Sicilian: Salsu), also known as the Imera Meridionale (Greek: Ἱμέρας; Latin Himera), is a river of Sicily. It rises in the Madonie Mountains (Latin: Nebrodes Mons; Sicilian: Munti Madunìi) and, traversing the provinces of Enna and Caltanissetta, flows into the Mediterranean at the western end of the Gulf of Gela at the seaport of Licata, in the Province of Agrigento. Its small deltaic system there is dominated by marine processes rather than fluvial ones. It is a seasonal torrent, with brief but violent floods during the winter rains (from November to February), and all but dry in summer droughts. In November 1915 the iron bridge across the river's mouth collapsed during floods, and 119 people were swept away in the flood and lost. The Salso, which is the longest river of Sicily at 132 kilometres (82 mi), has a drainage basin area of 2,022 square kilometres (781 sq mi).

The river's historically changeable meanders across the low coastal plain have been artificially channeled into the Canale di Sicilia, and the marshes drained for agriculture. Until the late nineteenth century it had two distributary channels, the second debouching 5 kilometres (3 mi) to the west. The mouth of the Salso has been advancing during historical times, and wind and wave formerly distributed its sand and silt to the beaches of the Gulf of Gela.