Papyrus 18 (in the Gregory–Aland numbering), designated by 𝔓¹⁸, is an early copy of the New Testament in Greek. It is a papyrus manuscript containing the beginning of the Book of Revelation. It contains only Revelation 1:4–7. It is written against the fibres of the papyrus. On the other side of the papyrus is the ending of the book of Exodus. It is unclear whether the papyrus was a scroll of Exodus later reused for a copy of Revelation or a leaf from a codex with miscellaneous contents. The two sides of the papyrus were copied in different hands, but the original editor of the papyrus did not think there was a great interval of time between the copying of the two sides. He assigned the Exodus to the third century and the Revelation to the third or early fourth century.

The Greek text of this manuscript is a representative of the Alexandrian text-type. Aland placed it in Category I.

It is currently housed at the British Library (Inv. 2053v) in London.

^a The scribe corrected this to τω θω