Ikūn-pî-Ištar, meaning “Ištar's word has come true”  and inscribed [i-k]u-un-pi4-eš4-tár, was a Mesopotamian king (ca. 1825–1799 BC short chronology) of uncertain jurisdiction, Jakobson suggested Uruk, presumably preceding Sîn-kāšid, contemporary with the latter part of the 1st Dynasty of Isin.
He appears on two variant Sumerian King List fragments, one of which has him followed by Sumu-abum (ca. 1830—1817 BC) of Babylon, the other sandwiched between the reigns of Erra-Imittī (ca. 1805–1799 BC) and Enlil-bāni (ca. 1798 BC – 1775 BC) the kings of Isin. This gives his reign as six months or a year depending on which variant is cited. Sūmû-El, the king of Larsa’s fifth year name (ca 1825 BC) celebrates a victory over the forces of Uruk during a time when it was independent. A haematite cylinder[i 1] seal in the British Museum attests to a servant of pî-Ištar, which may be an abbreviation of this king’s name. A satukku (sá-dug4), or offering, text from Nippur is the only exemplar of a text giving his year name and was found among a cache of cuneiform tablets relating to the temple of Ninurta dating from Lipit-Enlil’s first year (ca. 1798 BC) onward, after which the city remained under the control of the kings of Isin for a seventy five year period. His hegemony over this city must therefore have preceded that of Lipit-Enlil.
- Cylinder seal BM 121209.
- G. Suurmeijer (24–25 September 2010) "Identifiers and identification methods in legal documents from Old Babylonian Sippar (±1800-1500 BCE)," Conference "Legal Documents in Ancient Societies III," Leuven/Brussels, p. 1
- D O. Edzard (1999). "Ikūn-pî-Ištar". Reallexikon der Assyriologie und Vorderasiatischen Archäologie: Ia – Kizzuwatna. 5. Walter De Gruyter. p. 45.
- Thorkild Jakobson (1939). The Sumerian King List. University of Chicago Press. p. 8.
- Jean-Jacques Glassner (2005). Mesopotamian Chronicles. SBL. pp. 107–108, 154. Glassner’s manuscript’s C and D.
- Douglas Frayne (1990). Old Babylonian Period (2003-1595 B.C.): Early Periods, Volume 4. University of Toronto Press. p. 825.
- Nicole Brisch (Autumn 2011). "Old Babylonian satukku texts from Nippur". BISI Newsletter (28): 13.
- William W Hallo (1979). "God, king and man at Yale". State and Temple Economy in the Ancient Near East, Volume I. Peeters Publishers. p. 104.