Pompeia (fl. 1st century BC) was the second wife of Julius Caesar. Her parents were Quintus Pompeius Rufus, a son of a former consul, and Cornelia, the daughter of the Roman dictator Lucius Cornelius Sulla.
Caesar married Pompeia in 67 BC, after he had served as quaestor in Hispania, his first wife Cornelia having died the previous year in giving birth to her son who was stillborn. Caesar was the nephew of Gaius Marius, and Cornelia had been the daughter of Lucius Cornelius Cinna so that they were related to both the leaders of the losing populares side in the civil war of the 80s BC.
In 63 BC Caesar was elected to the position of Pontifex Maximus, the chief priest of the Roman state religion, which came with an official residence on the Via Sacra. In 62 BC Pompeia hosted the festival of the Bona Dea ("good goddess"), which no man was permitted to attend, in this house. However a young patrician named Publius Clodius Pulcher managed to gain admittance disguised as a woman, apparently for the purpose of seducing Pompeia. He was caught and prosecuted for sacrilege. Caesar gave no evidence against Clodius at his trial, and he was acquitted. Nevertheless, Caesar divorced Pompeia, saying that "my wife ought not even to be under suspicion." This gave rise to a proverb, sometimes expressed: "Caesar's wife must be above suspicion."