Necho, Or Neco (in the Bible also Pharaoh Necho, and in the hieroglyphics Neku), an Egyptian king of the 26th dynasty, who reigned, according to Rawlinson, from 610 to 594 B. C. He is called by Herodotus the son and successor of Psammetichus I., whose northeastern conquests he followed up with energy. He built a navy for the prosecution of maritime discovery, and began a canal to connect the Nile with the Arabian gulf, but is said to have abandoned this work because warned by an oracle that it would be used for the invasion of his country. Under his directions the Phoenicians circumnavigated Africa. He marched into Assyria to attack the Babylonians, and on his march defeated Josiah, king of Judah, in the valley of Megiddo (about 609). Advancing to the Euphrates, he took Carche-mish and established a garrison there. On his homeward march he deposed Jehoahaz, king of Judah, putting his brother Eliakim or Jehoiakim into his place, as a vassal of Egypt; and it is thought that about this time he took Jerusalem. Herodotus says that he took a city named Cadytis, but its identification with Jerusalem is not certain. Three years later Carchemish was attacked by Nebuchadnezzar, and Necho having marched to its relief was defeated and lost all his Asiatic dominions.

He never recovered from this blow, the rest of his reign being distinguished only by a weak and irresolute attempt to prepare for a new war against Babylon.