Ishbi-Erra (Akkadian: 𒀭𒅖𒁉𒀴𒊏 diš-bi-ir₃-ra) was the founder of the dynasty of Isin, reigning from c. 2017— 1986 BC (MC).

Puzur-Šulgi seems to have originally been one of Ishbi-Erra's own messengers and indicated the extent to which loyalties were in flux during the waning years of the regime of the third dynasty of Ur.

While there was no outright conflict, Ishbi-Erra continued to extend his influence as Ibbi-Sin's steadily declined over the next 12 years or so, until Ur was finally conquered by Kindattu of Elam.

Some years later, Ishbi-Erra ousted the Elamite garrison from Ur, thereby asserting suzerainty over Sumer and Akkad, celebrated in one of his later 27th year-name, although this specific epithet was not used by this dynasty until the reign of Iddin-Dagan.

[2] He readily adopted the regal privileges of the former regime, commissioning royal praise poetry and hymns to deities, of which seven are extant, and proclaiming himself Dingir-kalam-ma-na, "a god in his own country.