king of Egypt (reigned 610–595 BC), and a member of the 26th dynasty, who unsuccessfully attempted to aid Assyria against the Neo-Babylonians and later sponsored an expedition that circumnavigated Africa.

According to the Greek historian Herodotus, Necho began the construction of a canal from the Nile River to the Red Sea, probably in response to the growth of trade in the Egyptian Delta, but an oracle persuaded him to discontinue the project. A threat developed in Mesopotamia, where the Assyrian Empire was falling to the Babylonians. Necho ordered fleets to be built on the Mediterranean and Red seas, and with them he undertook a Syrian campaign in 608 BC to assist the battered Assyrian armies. When Josiah, king of Judah and an ally of the Neo-Babylonians, was slain in battle at Megiddo, Necho replaced Josiah's chosen successor with his own nominee and imposed tribute on Judah. In 606 the Egyptians routed the Neo-Babylonians, but at the great Battle of Carchemish (a Syrian city on the middle Euphrates River) in 605 the Neo-Babylonian crown prince, Nebuchadrezzar, soundly defeated Necho's troops and forced their withdrawal from Syria and Palestine. Egypt itself was threatened in 601, but Necho repelled the enemy and continued to promote anti-Babylonian coalitions in Syria and Palestine.

Herodotus also reports that Necho sent an expedition to circumnavigate Africa. His navigators apparently accomplished the feat, for they reported that, after a certain point in their voyage, the sun lay to their right (i.e., northward), as they sailed around southern Africa.