Decius Caecilius Metellus the Younger is a fictional character created by author John Maddox Roberts, the protagonist of Roberts's SPQR series of historical mystery novels. A Roman Senator during the waning days of the Roman Republic, Decius solves mysteries, while at the same time working his way steadily up the cursus honorum. 'Decius' is, nonetheless, an impossible Praenomen for the Republican period; the author may have been thinking of 'Decimus'.