Resheph (also Reshef and many other variants, see below; Eblaite 𒀭𒊏𒊓𒀊, Rašap, Ugaritic: 𐎗𐎌𐎔, ršp, Egyptian ršpw, Phoenician: 𐤓‬𐤔‬𐤐‬, ršp, Hebrew: רֶשֶׁף‎ Rešep̄) was a god associated with war and plague, originally worshiped in Ebla in the third millennium BCE. He was one of the main members of the local pantheon, and was worshiped in numerous hypostases, some of which were associated with other nearby settlements, such as Tunip. He was associated with the goddess Adamma, who was his spouse in Eblaite tradition. Eblaites considered him and the Mesopotamian god Nergal to be equivalents, most likely based on their shared role as war deities.

In the second millennium BCE, Resheph continued to be worshiped in various cities in Syria and beyond. He is best attested in texts from Ugarit, where he was one of the most popular deities. While well attested in ritual texts and theophoric names, he does not play a large role in Ugaritic mythology. An omen text describes him as the doorkeeper of the sun goddess, Shapash, and might identify him with the planet Mars. He was also venerated in Emar and other nearbly settlements, and appears in theophoric names as far east as Mari. The Hurrians also incorporated him into their pantheon under the name Iršappa, and considered him a god of commerce. Through their mediation, he also reached the Hittite Empire. He was also introduced to Egypt, possibly by the Hyksos, and achieved a degree of prominence there in the Ramesside period, with evidence of a domestic cult available from sites such as Deir el-Medina. The Egyptians regarded him as a warlike god, but he could also be invoked as a protective healer. He was associated with gazelles and horses, and in art appears as an armed deity armed with a bow, shield and arrows.

References to Resheph from the first millennium BCE are less common. He did not play a large role in Phoenician religion overall, with only one reference to him occurring in texts from Sidon, though he is well attested as a member of the Phoenician pantheon of Cyprus. He was also worshiped by Arameans in Cilicia and in Syria. References to him are also present in the Hebrew Bible, though due to the process of demythologization his name does not always refer to a personified deity. Greeks considered him an equivalent of Apollo, as attested by bilingual inscriptions from Cyprus, though it is not certain if this example of interpretatio graeca was recognized outside this island.

The etymology of Resheph's name is uncertain. According to Michael P. Streck, it is derived from the root ršp, and its cognates include Amorite yarśap (“to flame”), an element of personal names attested in texts from the Old Babylonian period, and the nominal rišp-, “flame” or “fever”, present in Hebrew and Aramaic. This possibility is the most commonly proposed explanation in scholarship, though it did not find universal support, and Maciej M. Münnich notes that it rests on biblical evidence, which comes at most from the sixth century BCE, in contrast with the oldest attestations of Resheph, which date back to the twenty-fourth century BCE, with no sources supporting this derivation from within the nearly two thousand year period separating them. Streck, despite his support for this proposal, acknowledges the nature of the connection between the presumed meaning of Resheph's name and his character is not fully clear. A second proposal is to link his name with Akkadian rašābu(m), “to destroy”, and rašbu(m), “terrifying, horrible” This view is supported by authors such as Jean-Marie Durand, but it similarly did not find universal support. Paolo Xella notes that all of the proposed etymologies might be the result of circular reasoning, as they depend on the available information about Resheph's character.

Cuneiform texts from Ebla render Resheph's name as Ra-sa-ap (𒊏𒊓𒀊). No further variants are attested in text from this city, and in most cases the name is preceded by the “divine determinative”, dingir (𒀭𒊏𒊓𒀊). The same spelling is also attested in sources from Mesopotamia and from Emar, though texts from this city also use variants such as Ra-ša-ap, Ra-šap and Ra-šap-pa.

In Ugarit, Resheph's name was written as ršp (𐎗𐎌𐎔) in the alphabetic script, and it is variously vocalized by Ugartiologists as Rašp, Rašap or Resheph. The writings Ra-ši-ip and Re-ša-ip appear in texts in standard syllabic cuneiform. Logographic ones are also attested, many of them derived from the various forms of the theonym Nergal: ^dGÌR.UNU.GAL(.LA), ^dMAŠ.MAŠ and ^dKAL (=^dLAMMA), though it is sometimes questioned if Resheph was necessarily meant in every case when they were used. The use of logograms originally linked to Nergal to represent Resheph is also well attested in texts from Ekalte, with identified examples including ^dGÌR, ^dIGI and ^dMAŠ.TAB.BA.

The Hurrian form of the name had a prothetic vowel affixed to it, resulting in spellings Aršappa and Iršappa, sometimes shortened to Iršap or Irša. The Hurrian variant is also attested in Ugarit as eršp. It has also been proposed that the variant name ^dRa-sa-pa-an developed through Hurrian influence too, but this view is not universally accepted.

Two forms of the name are attested in texts from ancient Egypt, ršp and ršpw, which might indicate a change in pronunciation occurred at some point, with the former writing reflecting Rashap, Rashp or Reshp and the latter - Rashpu or Reshpu, with a final u making the name easier to pronounce for speakers of Egyptian.