St. Cletus has given earlier historians some trouble because of his name. Two of the early lists of the popes, the so-called “Liberian Catalogue” and the “Poem Against Marcion” list an Anacletus as well as a Cletus. Most ancient lists, however, give the papal succession as Peter, Linus, Cletus, Clement; and modern scholars agree that this is the correct listing. Anacletus is a variant of Cletus, and this seems to have caused the difficulty.
The “Liber Pontificalis” says that his father was Emelianus and that Cletus was a Roman by birth, and belonged to the quarter known as the Vicus Patrici. It also tells us that he ordained twenty-five priests, and was buried in Vaticano near the body of St. Peter. St. Cletus’ feast is celebrated along with that of St. Marcellinus on the twenty-sixth of April.