Leto is the name of the mother of the twins Apollo and Artemis in Greek mythology by Zeus. When Hera found out that she was pregnant, she constantly pursued her from land to land, preventing her from giving birth. Leto eventually found refuge on the floating island of Delos and gave birth, first to Artemis (who apparently assisted her mother in delivering her brother) and than Apollo. In Roman mythology her counterpart is Latona. The origin of the name is uncertain. It has been linked to Lycian lada meaning “wife”, “mother”, or “woman, lady”, which would put it in the same etymological link as Leda, though it’s also been associated with Ancient Greek letho meaning “to forget; the hidden one” derived from PIE root word *leh₂- (to be hidden, to be covered).
Leto is also an Italian surname which comes from Latin Laetus, a Roman cognomen meaning “happy, joyful”.
Although traditionally a female name, it was used as a masculine name in Frank Herbert‘s Dune books, belonging to the main character’ father and his sons.
Origin: Lycian, Proto-Indo-European