Dyēus

' (), also ' (), is the reconstructed name of the daylight-sky god in Proto-Indo-European mythology. was conceived as a divine personification of the bright sky of the day and the seat of the gods, the . Associated with the vast diurnal sky and with the fertile rains, was often paired with *Dʰéǵʰōm, the Earth Mother, in a relationship of union and contrast.

While its existence is not directly attested by archaeological or written materials, is considered by scholars the most securely reconstructed deity of the Indo-European pantheon, as identical formulas referring to him can be found among the subsequent Indo-European languages and myths of the Vedic Indo-Aryans, Latins, Greeks, Phrygians, Messapians, Thracians, Illyrians, Albanians and Hittites.