The Lim bay (Croatian: Limski zaljev, Italian: Canale di Leme) and valley is a peculiar geographic feature found near Rovinj-Rovigno and Vrsar-Orsera on the western coast of Istria, south of Poreč-Parenzo, Croatia.

The name comes from the Latin limes for "limit", referring to the landform's position at the border of two Roman provinces: Dalmatia and Italia.

The Croats sometimes also call it Limski kanal ("Lim channel"), due to its narrow width.

Owing to its geological history, this estuary is one of the most instructive examples of limestone hydrological development.

The Lim stream used to flow through the valley but dried up regularly, and was really only present after the heavy rain.