Orpah is a character in the Hebrew Bible. She is from Moab, and was the daughter-in-law of Naomi, and wife of Mahlon.

After the death of her husband, Orpah and her sister-in-law Ruth wished to go to Judea with Naomi. She was persuaded, however, by Naomi to return to her people and to her gods (Ruth i. 4 et seq.).

In rabbinic literature Orpah is identified with Harafa, the mother of the four Philistine giants; and these four sons were said to have been given her for the four tears which she shed at parting with her mother-in-law (Babylonian Talmud, Sotah 42b).

According to a legend in a midrash, Orpah was a sister of Ruth; and both were daughters of the Moabite king Eglon (Ruth R. ii. 9). Her name was changed to "Orpah" because she turned her back on her mother-in-law (ib.; comp. Sotah l.c.) One source in the Talmud states that she was killed by King David's general Abishai, the son of Zeruiah (Sanhedrin 95a).