The temple of Leto was the largest of the three temples of the sanctuary named after the goddess. It is the best preserved. Because it was built on rocky ground, as were its two neighboring temples, it is protected from the seasonally increasing and decreasing groundwater level.

Leto is the daughter of the Titans Koios and Phoibe. She becomes a lover of Zeus. He begat with her the twins Artemis and Apollo. The Roman goddess Latona was later equated with her.