Not to be confused with the town of Navan in County Meath.

Navan Fort (Old Irish: Emain Macha , Modern Irish: Eamhain Mhacha is an ancient monument in County Armagh, Northern Ireland. According to tradition it was one of the great royal sites of pre-Christian Gaelic Ireland and the capital of the Ulaid. Severed heads of their enemies were said to be kept here. It is a large circular enclosure—marked by a bank and ditch—with a circular mound and the remains of a ring barrow in the middle. Archeological investigations show that there were once buildings on the site, including a huge roundhouse-like structure. The site is believed to have had a pagan ceremonial purpose. According to the Oxford Dictionary of Celtic Mythology, "the [Eamhain Mhacha] of myth and legend is a far grander and mysterious place than archeological excavation supports".