the lowermost division of Pliocene (Pliocene Epoch) rocks, representing all rocks deposited worldwide during the Zanclian Age (5.3 million to 3.6 million years ago) of the Neogene Period (the past 23 million years). The Zanclean Stage is named for Zancla, the pre-Roman name for Messina in Sicily.

The Global Stratotype Section and Point (GSSP) defining the lower boundary of this stage, ratified by the International Commission on Stratigraphy (ICS) in 2000, is located in the Eraclea Minoa section on the southern coast of Sicily. The lower boundary of the Zanclian Stage is nearly coincident with the first occurrence of Ceratolithus actus and the last occurrence of Discoaster quinqueramus; both species are calcareous nannoplankton (single-celled, photosynthetic organisms with shells made up of calcium carbonate plates called coccoliths (coccolith)). The upper boundary occurs just above the extinction margin of the foraminiferan (pseudopod-using unicellular organism protected by a test or shell) Globorotalia margaritae. The Zanclian Stage underlies the Piacenzian Stage and follows the Messinian Stage.