Jamshid ([dʒæmˈʃiːd]) (Persian: جمشید, Jamshīd) (Middle- and New Persian: جم, Jam) (Avestan: Yima) is a mythological figure of Greater Iranian culture and tradition.
In tradition and folklore, Jamshid is described as the fourth and greatest king of the epigraphically unattested Pishdadian Dynasty (before the Kayanian dynasty). This role is already alluded to in Zoroastrian scripture (e.g. Yasht 19, Vendidad 2), where the figure appears as Avestan language Yima(-Kshaeta) "(radiant) Yima," and from which the name 'Jamshid' is derived.
Jamshid remains a common Iranian and Zoroastrian male name. Edward FitzGerald transliterated the name as Jamshyd. In the eastern regions of Greater Iran, Central Asia, and by the Zoroastrians of the Indian subcontinent it is rendered as Jamshed.
The name Jamshid is originally a compound of two parts, Jam and shid, corresponding to the Avestan names Yima and Xšaēta, derived from the proto-Iranian *Yamah Xšaitah. Yamah and the related Sanskrit Yama are interpreted as "the twin," perhaps reflecting an Indo-Iranian belief in a primordial Yama and Yami pair. By regular sound changes (y → j, and the loss of the final syllable) Avestan Yima became Middle Persian Jam, which was subsequently continued into New Persian.