Oinanthe (Greek: Οἰνἀνθη) was a wife and widow of Agathocles (the elder) and the mother of Agathocles (the younger) and Agathokleia. After the death of Agathocles (the elder), she married Theogenes.
Oinanthe introduced Agathokleia and Agathokles (the younger) to Ptolemaios IV, and Agathokleia became Ptolemaios IV's mistress, while Agathokles (the younger) became a minister. Agathokleia and her brother wielded much influence over Ptolemaios IV.
When Ptolemaios IV died, Agathokleia, Agathokles (the younger), and another influential minister named Sosibios had Philammon assassinate queen dowager Arsinoe III Philopator so that Agathokles (the younger) and Sosibios could serve as regents for Arsinoe's young son Ptolemais V Epiphanes. Agathokles later had Sosibios killed as well.
The people learned of the truth behind Arsinoe's death. Agathokles (the younger) was killed, and a mob killed and dismembered Oinanthe, Agathokleia, and Oinanthe's daughters. A mob also killed Philammon.
Tlepolemos then became Ptolemaios V's regent.