According to the Bible, Ruth’s mother-in-law was Naomi. Their relationship is central to the Book of Ruth, where Naomi’s family tragedy and Ruth’s loyalty drive the story.
Naomi was married to Elimelech, and the couple moved from Bethlehem to Moab during a famine. Their two sons married Moabite women, Ruth and Orpah. After Elimelech and both sons died, Naomi decided to return to Bethlehem. Orpah stayed in Moab, but Ruth chose to accompany Naomi and adopt her people and homeland.
Back in Bethlehem, Naomi helped guide Ruth toward Boaz, a relative of Elimelech who could act as a family redeemer. Ruth and Boaz married and had a son named Obed. Naomi became Obed’s nurse, and the child was later identified as the grandfather of King David.
A common mix-up is confusing Naomi with Orpah: Orpah was Ruth’s sister-in-law, while Naomi was her mother-in-law. Naomi is also briefly associated with the name Mara, meaning “bitter,” after her losses.