The Imera Settentrionale (Greek: Ἱμέρας, Latin: Himera; Italian: Imera Settentrionale or also Fiume Grande) is a river of Sicily, rising in the Western Madonie mountains near Cozzo Levanche, and flowing approximately 35 kilometres (22 mi) through the comuni of Caltavuturo, Campofelice di Roccella, Cerda, Collesano, Scillato, Sclafani Bagni, Termini Imerese and Valledolmo (all in the Province of Palermo) to the Tyrrhenian Sea at the site of the ancient city of Himera.

The drainage area is 342 square kilometres (132 sq mi), making it one of the principal rivers of Sicily to flow into the Tyrrhenian.

[1] Himera was the ancient name of two rivers in Sicily, the Imera Settentrionale flowing to the north into the Tyrrhenian Sea, the other (the Salso) to the south coast of the island, but which, by a strange confusion, were regarded by many ancient writers as one and the same river, which is in consequence described as rising in the center of the island, and flowing in two different directions, so as completely to divide Sicily into two parts.

It is singular that, if we may believe Vibius Sequester, this absurd notion is as old as the time of Stesichorus, who was himself a native of the city of Himera.

[4] Hence its identification with the modern Imera Settentrionale (or Fiume Grande) was necessarily connected with the determination of the site of that city, a question which was the subject formerly of dispute.