Ishmekarab (Išmekarab) or Ishnikarab (Išnikarab) was a Mesopotamian deity of justice. The name is commonly translated from Akkadian as "he heard the prayer," but Ishmekarab's gender is uncertain and opinions of researchers on whether the deity was male or female vary.

In Mesopotamia Ishmekarab was worshiped as a member of various groups of judge deities, including the "standing god of Ebabbar" and as part of the group of "divine judges" attested in Assyria from between the period of Erishum I's reign and the era of the Neo-Assyrian Empire. Many attestations are also known from Susa in Elam, where a number of deities of Mesopotamian origin were worshiped.

Ishmekarab was a deity of justice, described as a divine judge and in some cases invoked in legal formulas. In this role, as well as in that of an oath deity, Ishmekarab could be associated with Shamash. A curse formula from Susa written in Akkadian mentions the scepter of Ishmekarab as a symbolic deterrent against altering the text it was a part of. Similarly, oath breakers were said to risk having their skull smashed by this weapon. A seal inscription from Susa indicates that Ishmekarab was also believed to repel the utukku demons, not otherwise attested in texts from that city.

In Susa, Ishmekarab was associated with Inshushinak and Lagamal. Nathan Wasserman refers to Lagamal and Ishmekarab as a couple. Wouther Henkelman assumes that during judgment in the afterlife attested in texts from Susa, Ishmekarab played the role of advocatus dei, in contrast with Lagamal, who he identifies as advocatus diaboli. Wilfred G. Lambert notes that despite a possible association with the underworld present in so-called Susa funerary texts, Ishmekarab should not be regarded as an underworld deity, and generally appears to be a deity dwelling elsewhere, above ground.

It is possible that a minor deity depicted alongside a god on a snake throne (Inshushinak or Napirisha) on Elamite cylinder seals can be identified as Ishmekarab.

Milad Jahangirfar notes that the gender of Ishmekarab is uncertain, and there is no consensus among researchers regarding this topic.

Wilfred G. Lambert describes the view that Ishmekarab was female as "common but unfounded." He notes that while the verb forms used to describe the actions of Ishmekarab and Lagamal in the so-called "Susa funerary texts" do leave the possibility that they were not two gods but a god and a goddess, there is no clear evidence otherwise. Manfred Krebernik also considers Ishmekarab to be a male deity, and translates the name accordingly with the masculine pronoun as "he heard the prayer" ("Er erhörte das Gebet"). De Graef recently translated a seal dating to the Sukkalmah period as reading "Ishmekarab, king of the city of Susa," and Tavernier, who already believed Ishmekarab to be male, considers this convincing proof that Ishmekarab was a god and not a goddess.

However, other scholars see Ishmekarab as female. For example Florence Malbran-Labat, although recognizing that Ishmekarab being a goddess is disputed, considers Ishmekarab to be a goddess, and possibly the spouse of Inshushinak. This view is also supported by Daniel T. Potts, who refers to Ishmekarab as the "lady of the siyan kuk" ("sacred precinct") at Chogha Zanbil. Wasserman appears to believe that Ishmekarab and Lagamal were a couple.