The English word papyrus derives, via Latin, from Greek πάπυρος papyros. Greek has a second word for papyrus, βύβλος byblos (said to derive from the name of the Phoenician city of Byblos). The Greek writer Theophrastus, who flourished during the 4th century BC, uses papuros when referring to the plant used as a foodstuff and bublos for the same plant when used for non-food products, such as cordage, basketry, or a writing surface. This latter usage finds its way into English in such words as bibliography, bibliophile, and bible. Papyrus is also the etymon of paper, a similar substance.

The plural of papyrus is papyri.

It is often claimed that Egyptians referred to papyrus as pa-per-aa [p3y pr-ˁ3] (lit., "that which is of Pharaoh"), apparently denoting that the Egyptian crown owned a monopoly on papyrus production. However no actual ancient text using this term is known. In the Egyptian language, papyrus was known by the terms wadj [w3ḏ], tjufy [ṯwfy], and djet [ḏt]. Thus in reality, Greek papyros has no known relation to any Egyptian word or phrase.