The Omphalos (Greek: " ὀμφαλός ", " navel " ) was a phallic cult stone in Adyton the temple of Apollo in Delphi. He was covered with woolen garlands ( Agrenon ) and marked the ' navel of the world ". A Hellenistic or Roman marble copy of the stone is now in the Archaeological Museum of Delphi.

The Omphalos to be dropped after the announcement as a meteor from the sky. He was worshiped in the sanctuary of Apollo. Originally it was probably a sacrificial stone of the goddess Gaia, and marks the point at which the delegates of Zeus in the far west and the far east eagles have taken in the middle of the world. According to Pausanias, he was the world axis, the mythical link between heaven, earth and underworld. Under him is said to be the grave of Dionysus, also Python to have been buried under it.

With " Omphalos " and later the rule laid down in the Roman Forum was called umbilicus. This stone was the Romans as a center of the world. In Delphi there was also the stone which Rhea, according to the myth instead of the newborn Zeus gave her husband Kronos for entangling and the Kronos spit out later. The Stone of Kronos was similarly revered as the Omphalos and other Baityloi and can therefore be confused with this.

In addition to Apollo and Asklepios statues are shown with the Omphalos. There may be a transfer of the attribute of Apollo.

As omphalos bowl is referred to in the ancient ceramic one type of shallow round bowls that are equipped with a central hump and served as sacrificial bowls. Derived from the central hump of shells is also called later periods of art as Omphalos occasionally; they often had only a decorative purpose or served as an abutment for the base ring associated cans.