Damgalnuna, also known as Damkina, was a Mesopotamian goddess regarded as the wife of the god Enki. Her character is poorly defined in known sources, though it is known that like her husband she was associated with ritual purification and that she was believed to intercede with him on behalf of supplicants. Among the deities regarded as their children were Nanshe and Asalluhi. While the myth Enki and Ninhursag treats her as interchangeable with the goddess mentioned in its title, they were usually separate from each other. The cities of Eridu and Malgium were regarded as Damgalnuna's cult centers. She was also worshiped in other settlements, such as Nippur, Sippar and Kalhu, and possibly as early as in the third millennium BCE was incorporated into the Hurrian pantheon. She appears in a number of myths, including the Enūma Eliš, though only a single composition, Damkina's Bond, is focused on her.

The theonym Damgalnuna can be translated as "the great wife of the prince," the "prince" implicitly being Enki. Joan Goodnick Westenholz pointed out that the writing of her name with the cuneiform sign NUN reflects her connection with the city of Eridu, as it was used as a logographic representation of its name. Shortened writings include ^ddam-gal and possibly ^ddam. It is agreed that the second form of her name, Damkina, developed later. In late sources it could be spelled as Damkianna. This form is attested in Neo-Babylonian letters found in Uruk, according to Paul-Alain Beaulieu originally sent from Eridu. Further variant spellings such as Damnun, Damnuna and Damgalana are also attested. The Hurrian form of the name was Tapkina.

Damgalnuna's individual character was poorly defined beyond her spousal relation with Enki. She was believed to intercede with him on behalf of human supplicants, which has been compared to an analogous role attested for Adad's wife Shala, Shamash's wife Aya, Ishum's wife Ninmug or Inanna's attendant Ninshubur. Like Enki, Damgalnuna could be associated with exorcisms and ritual purification. In incantations, she could be invoked against demons.

It has been proposed that cylinder seal depictions of a goddess accompanied by Enki's symbolic hybrids, the fish man and the fish goat, on cylinder seals who can be identified as Damgalnuna. Julia M. Asher-Greve points out that sometimes she appears in the same scenes on them as Enki. It has also been suggested that lions might have been her symbolic animals.

In Mesopotamian astronomy, Damgalnuna was identified with the constellation Wagon of Heaven, corresponding to Ursa Minor.

Damgalnuna was the wife of Enki (Ea). In the myth Enki and Ninhursag, she and the eponymous goddess are treated as the same deity. However, Dina Katz points out that they were usually separate, and Ninhursag's husband was Šulpae. Deities considered to be children of Enki and Damgalnuna include Nanshe, Asalluhi, Marduk and Enbilulu.

In a variant of the Weidner god list, Damgalnuna is equated with Kiša, the wife of the river god Idlurugu. An Emesal vocabulary apparently mistakes her and her husband for the primordial deities Enki and Ninki. Despite their similar names, the two Enkis were not identical. Multiple alternate names are assigned to Damgalnuna in the god list An = Anum (tablet II, lines 173-184), including Ningikuga and Ninti. It has been argued that the latter name is also used to refer to her in the Hymn to Ninkasi, where this goddess is the mother of the eponymous beer deity. According to Antoine Cavigneaux and Manfred Krebernik, Ningikuga as a name of a spouse of Enki is to be distinguished with the use of this name to refer to the mother of Ningal or to Ningal herself.

The deities Ḫasīsu and Uznu, "wisdom" and "ear," were considered Damgalnuna's divine attendants (sukkals).