Publius Aelius Paetus was apparently the elder surviving son of Quintus Aelius Paetus, a praetor who was killed at Cannae in August 216 BC.
His younger brother was Sextus Aelius Paetus Catus who became consul in 198 BC and censor in 194 BC, and is best known to us via Cicero as a jurist and commentator on the Twelve Tables.