Macha was a sovereignty goddess of ancient Ireland associated with the province of Ulster, particularly the sites of Navan Fort and Armagh, which are named after her. Several figures called Macha appear in Irish mythology and folklore, all believed to derive from the same goddess. She is said to be one of three sisters known as 'the three Morrígna'. Like other sovereignty goddesses, Macha is associated with the land, fertility, kingship, war and horses.

Navan Fort is an ancient ceremonial monument near Armagh, Northern Ireland. According to tradition it was one of the great royal sites of pre-Christian Gaelic Ireland and the capital of the Ulaidh. It is a large circular hilltop enclosure—marked by a bank and ditch—inside which is a circular mound and the remains of a ring barrow. Archeological investigations show that there were once buildings on the site, including a huge roundhouse-like structure that has been likened to a temple. In a ritual act, this timber structure was filled with stones, deliberately burnt down and then covered with earth to create the mound which stands today. It is believed that Navan was a pagan ceremonial site and was regarded as a sacred space. It features prominently in Irish mythology, especially in the tales of the Ulster Cycle. 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".