This article is about the Egyptian city. For the Italian spiritual community see Federation of Damanhur

Damanhur (Arabic: دمنهور ) is a city in Lower Egypt, and the capital of al-Buhayrah (Beheira or Behera) governorate. It is located 160 km northwest of Cairo, and 70 km E.S.E. of Alexandria, in the middle of the western Nile Delta, at . It is an important communications center.

It was once the site of the city of Tmn-Hor, which was dedicated to the ancient Egyptian god Horus. In Greek and Roman times it was called Hermopolis Parva which would also give it an association with Hermes, the Egyptien Thoth.

The 1986 population was 188,939. The richly-cultivated Beheira province gives rise to mainly agricultural industries which include cotton ginning, potato processing, and date picking. It also has a market for cotton and rice.

Ahmed H. Zewail, who won the Nobel Prize for Chemistry in 1999, was born here in 1946.