How many currencies are there in the world?

168 according to the Universal Currency Converter:
There are as many currencies as there are populated countries.

Actually there are rather less, seeing as some countries share the same currency (E.G. the Eurozone). In terms of official currencies, there are 168 according to the Universal Currency Convertor but there may be many other things people use to represent money which are not official currencies.

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There are currently 168 internationally recognized unique national currencies, but in the exact question you asked, World Currencies, there are only 2: the US dollar and the Euro.