In Greek mythology, Borysthenis () may refer to two distinct individuals:

 Borysthenes, one of the three Muses that were daughters of Apollo. Her sisters were Apollonis and Cephisso.
 the Scythian Earth-and-Water goddess Api, who was called  because she was the daughter of the god of the Borysthenēs river (now the Dnipro river).

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Greek Muses
Children of Apollo
Naiads