Benthesikyme in Greek mythology according to Apollodorus (3.15.4), was a daughter of Poseidon and Amphitrite and wife of an unnamed Ethiopian by whom she had two daughters. She raised Eumolpus, son of Chione and Poseidon.

When Chione gave birth, she was so frightened of her father's reaction that she threw the baby into the ocean. As Apollodorus relates:

But Poseidon picked him up and conveyed him to Ethiopia, and gave him to Benthesikyme (a daughter of his own by Amphitrite) to bring up. When he was full grown, Benthesicyme's husband gave him one of his two daughters. But he tried to force his wife's sister...

Accordingly Eumolpus was sent into exile.