Keturah (Hebrew: קְטוּרָה, Qəṭūrā, possibly meaning "incense"; Arabic: قطورة) was a wife and a concubine of the Biblical patriarch Abraham. According to the Book of Genesis, Abraham married Keturah after the death of his first wife, Sarah. Abraham and Keturah had six sons. According to Jewish tradition, she was a descendant of Noah's son Japheth.

One modern commentator on the Hebrew Bible has called Keturah "the most ignored significant person in the Torah". The medieval Jewish commentator Rashi, and some previous rabbinical commentators, related a traditional belief that Keturah was the same person as Hagar, although this idea cannot be found in the biblical text. However, Hagar was Sarah's Egyptian maidservant.

Keturah is mentioned in two passages of the Hebrew Bible: in the Book of Genesis and in the First Book of Chronicles. Additionally, she is mentioned in Antiquities of the Jews by the 1st-century Romano-Jewish historian Josephus, in the Talmud, the Midrash, the Targum on the Torah, the Genesis Rabbah, and various other writings of Jewish theologians and philosophers.

Louis Feldman has said "Josephus records evidence of the prolific non-Jewish polymath Alexander Polyhistor, who in turn cites the historian Cleodemus Malchus, who states that two of the sons of Abraham by Keturah joined Heracles' campaign in Africa, and that Heracles, without doubt the greatest Greek hero of them all, married the daughter of one of them."

According to Doctor of Anthropology Paula M. McNutt, it is generally recognized that there is nothing specific in the biblical traditions recorded in Genesis, including those regarding Abraham and his family, that can be definitively related to known history in or around Canaan in the early second millennium B.C.

Keturah is referred to in Genesis as "another wife" of Abraham (Hebrew: אִשָּה‎, romanized: 'išāh, lit. 'woman, wife'). In First Chronicles, she is called Abraham's "concubine" (Hebrew: פִּילֶגֶשׁ‎, romanized: pilegeš, lit. 'concubine').

According to one opinion in the midrashic work Genesis Rabbah, Keturah and Hagar are names for the same person, whom Abraham remarried after initially expelling. This opinion was adopted and popularized by 11th-century scholar Rashi. Possible justifications for this opinion include the fact that Keturah is referred to 1 Chronicles 1:32 as Abraham's concubine (in the singular), and several other verses which suggest that the descendants of Hagar and Keturah lived in the same territory or formed a single ethnic group. However, this idea was rejected by another rabbi in Genesis Rabbah, as well as by traditional commentators such as Ibn Ezra, Nahmanides, and Rashbam. The Book of Jubilees also supports the conclusion that Keturah and Hagar were two different people, by stating that Abraham waited until after Sarah's death before marrying Keturah. According to modern scholar Richard Elliott Friedman, the identification of Keturah with Hagar has "no basis ... in the text".

Genesis Rabbah interprets the name Keturah in accordance with the opinion that she was identical to Hagar: the name was said to be related to the Aramaic ketur (knot) to imply that she was "bound" and did not have sexual relations with anyone else from the time she left Abraham until her return. The name Keturah was alternatively said to be derived from the ketoret (meaning "incense" in Hebrew).