Phyllis is a character in Greek mythology. She was the daughter of Lycurgus, King of Thrace who married Demophoon, son of Theseus, while he stopped in Thrace on his journey home from the Trojan war.

Demophoon, duty bound to Greece, returns home to help his father, leaving Phyllis behind. She sends him away with a coffin with the sacrament of Rhea, asking him to open it only when he has given up hope of returning to her. From here, the story diverges. In one version, Phyllis commits suicide by hanging herself from a tree. Where she is buried, an almond tree grows, which blossoms when Demophoon returns to her. In a second version of the story, Demophoon opens the caskets and accidently falls on his own sword.

This story most notably appears in Book II of Ovid's epistolary epic, the Heroides, and also appears in the work of Callimachus.

The Nine Ways is derived from the story of Phyllis, who is said to have return nine times to the shores to wait for Demophoon's return.

See: Fulkerson, Laurel. "Reading dangerously: Phyllis, Dido, Ariadne, and Meda". The Ovidian Heroine as Author. Cambridge: Cambridge University Press, 2005.