Can The Fifth Sibylline Oracle be useful for the study of Second Temple Judaism? J.J. Collins thought so, and John M.G. Barclay has attempted to use it in his construction of Jewish life and thought in the Mediterranean Diaspora. But David S. Potter and Erich Gruen have cautioned that because the Sibylline Oracles were preserved by Christians and subjected to extensive redaction and interpolation, they cannot be dated with any certainty and therefore cannot be reliably used for the study of Second Temple Judaism. In this article I attempt to identify and date two clear strata in The Fifth Sibylline Oracle, explaining how the document came into its final, or near-final form. Then I make some preliminary suggestions regarding what The Fifth Sibylline Oracle may tell us about Second Temple Judaism.