The Riphean is a stage or age of the geologic timescale from 1,600 to 600 million years ago.

The name Riphean is used in the Proterozoic stratigraphy of Russia and the Fennoscandian Shield in Finland.

[1] It was also used in a number of older international geologic timescales but, in the most recent timescales of the ICS, it is replaced by the Calymmian, Ectasian, Stenian, Tonian and Cryogenian periods of the Neoproterozoic and Mesoproterozoic eras.

During the Riphean, there was a great increase in stromatolite diversity, possibly related to the appearance of eukaryotes.

[1][3] This geochronology article is a stub.