Selemnos (Ancient Greek: Σέλεμνος, Latin: Selemnus) is a river in the northern part of Achaea, Greece.

The river flows entirely in the municipal unit of Rio and empties into the Gulf of Corinth.

The river begins on the northwest side of the Panachaiko mountain.

That time, the goddess Aphrodite made him a river, the waters of which were believed to cure of unrequited love.

[1] The story of Selemnus is referenced in a tale by Rena Galanaki in Mnimi tou erota, lithi tou erota (Μνήμη του έρωτα, λήθη του έρωτα) in the book Ena schedon galazio cheri ( σχεδόν γαλάζιο χέρι) (Kastaniotis, 2004) and one poem Sto Kastritsianiko potami (Στο Καστριτσιάνικο ποτάμι = By The Kastritsianiko River) by Thodoris Gkonia and Nikos Xydakis.