In Roman mythology, Clitumnus (;) was a son of Oceanus and Tethys. He was the god of the Clitunno River in Umbria.
Reference to Clitumnus is best attested in Pliny the Younger "Letters" 8.8: "Hard by is an ancient and sacred temple, where stands Jupiter Clitumnus himself clad and adorned with a toga praetexta, and the oracular responses delivered there prove that the deity dwells within and foretells the future."[1]
The Roman Emperor Caligula visited the sacred grove prior to his invasion of Germany, presumably to consult the oracle of Clitumnus.[2] [3]