Poppaea Sabina (died 65) was the second wife of the Roman Emperor Nero. She was one of the most infamous women of Ancient Rome.

Sabina was the daughter of Titus Ollius, a praetor in the reign of the Emperor Tiberius. His friendship with Sejanus ruined him, before gaining public office. Her mother, also called Poppaea Sabina, was a distinguished woman, whom the ancient sources describe as a wealthy beauty and a woman of distinction. Tacitus describes her as one of the loveliest women of her day. In A.D. 47, she committed suicide as an innocent victim of the intrigues of Empress Messalina.

The father of the elder Sabina was Gaius Poppaeus Sabinus, who was consul of A.D. 9. In Tiberius’ reign, he received a miliary triumph, for ending a revolt in Thrace in A.D. 26. From A.D. 15 until his death, he served as Imperial Governor of Greece and in other provinces. This competent administrator enjoyed the friendship of the imperial family. He died in A.D. 35.

Poppaea Sabina had a stepfather called Publius Cornelius Lentulus Scipio. He served as a divisional commander in A.D. 22, consul in A.D. 24 and later senator. Her half-brother of the same name was consul in A.D. 56 and later served as a senator.

Poppaea Sabina's first marriage was to Rufrius Crispinus, a man of equestrian rank. He was the leader of the Praetorian Guard during the reign of the Emperor Claudius. In A.D. 51, the Empress Agrippina removed him from this position; as he favoured Messalina and her children and was later executed. She had borne him a son of the same name. Later Nero drowned him on a fishing trip after her death.

Later on she briefly married future Emperor Otho, while being a mistress to the Emperor Nero.

Ambitious and ruthless, Poppaea was initially Nero's favourite mistress. Even as a mistress, she was hated and feared by many in Rome. It is said that Nero's mother Agrippina the Younger, saw the danger and tried to persuade Nero to get rid of her. This dispute over Poppaea was one of the reasons that saw Nero finally murder his mother. With Agrippina gone, Poppaea's influence over Nero became so great that due to the pressure she put on him, he divorced (and later executed) his first wife Octavia in order to marry Poppaea in A.D. 62. The new empress had many other unfortunates who challenged her power murdered or sent into exile. Nero's former tutor Seneca is thought to be among her victims. In some Church sources it is claimed that it was Poppaea and not Nero who instigated the persecutions against Christians, in order to cover up her murderous deeds.

She bore Nero one daughter, Claudia Augusta, who died at only four months old.

According to Suetonius, while she was awaiting the birth of her second child, she quarreled fiercely with Nero over his spending too much time at the games. In a fit of rage, Nero kicked her in the abdomen, so causing her death.

The opera L'Incoronazione di Poppea by Claudio Monteverdi concerns her life.