Achish ( ʾāḵīš, Philistine: 𐤀𐤊𐤉𐤔 *ʾākayūš, Akkadian: 𒄿𒅗𒌑𒋢 i-ka-ú-su) is a name used in the Hebrew Bible for two Philistine rulers of Gath. It is perhaps only a general title of royalty, applicable to the Philistine kings. The two kings of Gath, which most scholars identify as Tell es-Safi, are: The Latin transliteration "Achish" represents the begadkefat (aspiration over a medial stop) in Aramaic and in post-Biblical Hebrew. Before the strong influence of Aramaic over Hebrew, which occurred after the Babylonian captivity, אָכִישׁ would have been pronounced: "Akish." In the seventh-century BCE Ekron Royal Dedicatory Inscription, the name Akish appears as "son of Padi, son of, son of Ada, son of Ya'ir"; Akish by then held enough authority in Ekron to dedicate a temple. A similar name, Ikausu, appears as king of Ekron in seventh-century BCE Assyrian inscriptions, as does Padi. Scholars agree that these two are the same men, although a royal status cannot yet be confirmed for their ancestors Ysd, Ada, and Ya'ir. This appears to indicate that either the name "Akish" was a common name for Philistine kings, used both at Gath and Ekron, or, as Naveh has suggested, that the editor of the biblical text used a known name of a Philistine king from the end of the Iron Age (Achish of Ekron) as the name of a king(s) of Gath in narratives relating to earlier periods.

In literature

Achish of Gath is a supporting role in the 17th-century opera David et Jonathas, sung by a bass. Achish king of Gath appears in the 1985 film King David, starring Richard Gere.