Rhea \r-hea\ as a girl's name is pronounced REE-ah. It is of Greek origin, and the meaning of Rhea is "flowing". Mythology: Rhea was the mother of Zeus, Poseidon, Hera, and Demeter. Rhea is also a Welsh name referring to a river in Wales. Actress Rhea Perlman.
For more information, see also the related name Cybele.