Kiya was one of the wives of the Egyptian Pharaoh Akhenaten. Little is known about her, and her actions and roles are poorly documented in the historical record, in contrast to those of Akhenaten's 'Great royal wife', Nefertiti. Her unusual name suggests that she may originally have been a Mitanni princess. Surviving evidence demonstrates that Kiya was an important figure at Akhenaten's court during the middle years of his reign, when she had a daughter with him. She disappears from history a few years before her royal husband's death. In previous years, she was thought to be mother of Tutankhamun, but recent DNA evidence suggests this is unlikely.

The name Kiya itself is cause for debate. It has been suggested that it is a "pet" form, rather than a full name, and as such could be a contraction of a foreign name, such as the Mitanni name "Tadukhipa," referring to the daughter of King Tushratta. Tadukhipa married Amenhotep III at the very end of his reign, and the Amarna Letters indicate that she was of marriageable age at that time. In particular, Amarna Letters 27 through 29 confirm that Tadukhipa became one of Akhenaten's wives. Thus some Egyptologists have proposed that Tadukhipa and Kiya might be the same person.

However, there is no confirming evidence that Kiya was anything but a native Egyptian. In fact, Cyril Aldred proposed that her unusual name is actually a variant of the Ancient Egyptian word for "monkey," making it unnecessary to assume a foreign origin for her.

In inscriptions, Kiya is given the titles of "The Favorite" and "The Greatly Beloved," but never of "Nobelwoman (iryt-p‘t)" or "Great Royal Wife", some believe this indicates that she was not of royal Egyptian blood, but in fact the two are not causally related. Many queens of royal descent have not been shown to bear these titles, such as Mutnofret, the Younger Lady, and Tanedjemet. Her full titles read, "The wife and greatly beloved of the King of Upper and Lower Egypt, Living in Truth, Lord of the Two Lands, Neferkheperure Waenre, the Goodly Child of the Living Aten, who shall be living for ever and ever, Kiya." All artifacts relating to Kiya derive from Amarna, Akhenaten's short-lived capital city, or from Tomb KV55 in the Valley of the Kings. She is not attested during the reign of any other pharaoh.

Kiya's existence was unknown until 1959, when her name and titles were noted on a small cosmetic container in the collection of the Metropolitan Museum of Art. It had been bought almost thirty years previously, without provenance, from Egyptologist Howard Carter.

The British Egyptologists Aidan Dodson and Dyan Hilton wrote:

Akhenaten and his family were based in Thebes for the first four years of his reign, establishing the new capital city at Amarna in Year 5. Kiya is not attested during this early period. Only after the move to Amarna does she emerge through inscriptional evidence as one of Akhenaten's wives.

Kiya's name appeared prominently in the temple installation known as the Maru-Aten, at the southern edge of the city, according to epigraphic studies. The inscriptions in the Maru-Aten were eventually recarved to replace the name and titles of Kiya with those of Akhenaten's eldest daughter, Meritaten.