Hermus is the god of the river Hermus (modern Gediz river) located in the Aegean region of Lydia (modern Turkey). Like most of the river-gods, he is the son of Oceanus and Tethys. He was the father of the Lydian nymphs.
Son of Aegyptus
Hermus was a nobleman of Athens and a companion of Theseus. When Theseus founded the city of Pythopolis, he left Hermus there. A place in Pythopolis called the House of Hermes was named after him, incorrectly changing the name to that of a god.