In Greek mythology, Pandora’s father-in-law was Iapetus according to Hesiod’s family story.
Pandora is linked to Epimetheus, one of the Titans Iapetus’s sons. Iapetus is therefore identified as Pandora’s father-in-law in genealogical summaries of the myth. Iapetus himself is a Titan and the son of Uranus, the sky, and Gaia, the earth. His other famous sons include Prometheus, Atlas, and Menoetius.
This family connection can be confused with Pandora’s more famous relationship to Prometheus. Prometheus and Epimetheus are brothers, while Pandora is associated with Epimetheus. The myth is not consistent across every ancient source or later retelling, and some accounts describe Pandora as the first woman without developing a complete family tree. Still, Iapetus is the canonical answer when the question follows Hesiod’s Titan genealogy.