Tiglath-Pileser III or IV (or Tilgath-Pil-neser or Tiglatpilesar III), was a prominent king of Assyria in the 8th century BC (ruled 744–727 BC).

The name Tiglath-Pileser was a throne-name — that is, one given to the king on his accession to the throne, rather than a name given at birth. In translation, it means "my confidence is the son of Esarra." It is given in several different forms in historical records. The Bible records him as Tillegath-pilneser (2 Chronicles 28:20) and the much-abbreviated Pul (1 Chronicles 5:26 and 2 Kings 15:19,20). In Assyrian cuneiform, his name is given as Tukulti-apil-esarra, which has been rendered into modern languages as Tiglath-Pileser.

His origins are unknown but he may have been a usurper who assumed the name of a more legitimate predecessor. Under his rule, Assyrian power in the Near East greatly increased as the result of campaigns of conquest mounted against western kingdoms. Assyrian inscriptions record, in the fifth year of his reign (739 BC), a victory over Azariah (Uzziah), king of Judah, whose achievements are described in 2 Chronicles 26:6-15. In 733 BC his armies conquered Philistia on the Mediterranean coast, destroyed Damascus and occupied most of Israel, with its northern regions becoming Assyrian provinces. Many of the inhabitants were enslaved and deported to other parts of the Assyrian empire.

These events were recorded in the Bible, which describes how Tiglath-Pileser III defeated Pekah, king of Israel, and Rezin , king of the Arameans, who had allied against him. He executed Rezin and Pekah was murdered by Hoshea, who took control of the rump Israelite kingdom as a vassal paying tribute to the Assyrians. (2 Kings 15:29; 16:5-9; 1 Chronicles 5:6, 26) Ahaz (known to the Assyrians as Yahu-khazi), the king of Judah, was also forced to pay tribute to the Assyrian conqueror (2 Kings 16:10-16).

Tiglath-Pileser III's conquests paved the way for the establishment of the Second Assyrian Empire. On his death, the Assyrian throne was seized by Ululai, the governor of Babylon, who assumed the name Shalmaneser V.