Titus Prifernius Geminus was a Roman senator who lived in the second century. He is best known as a friend and correspondent of Pliny the Younger, who addresses him as Geminus; he served as quaestor to Pliny for the latter's consulship in AD 100, and five letters Pliny wrote to Geminus have survived. Although the letters convey a genuine friendship between the two, the first one appears only in the latter books of Pliny's collection; Ronald Syme explains this may be due to the fact that he, like Quintus Corellius Rufus and Calestrius Tiro, were living in Rome at the same time.