Cornelia was an ancient Roman chief Vestal virgin (Vestalis Maxima) convicted of and executed for unchastity around the year 90 CE. Suetonius, a 1st-century CE historian, records that she had been previously tried for a crime but was then acquitted. However, following her second trial, she was convicted and sentenced to live burial and her lover was beaten to death with rods in the Comitium. The Emperor Domitian (r. 81–96) did permit one of her paramours, an ex-praetor, to survive, supposedly because he had confessed to the crime before the case had been concluded and because the torture of the witnesses had not yielded any results.
Pliny the Younger, a 1st-century Roman author, states that Domitian was furious at the lack of witnesses for this case, though he had already resolved to execute Cornelia so as to render his reign famous for having had such a significant trial occur during his tenure as emperor. According to Pliny, Domitian summoned the College of Pontiffs to discuss the case, though he set the meeting to take place within his Alban palace rather than in the Regia, their traditional gathering spot. She was allegedly condemned in absentia without any opportunity to present a defense. Pliny writes that, whilst being led to the spot of her execution, she supposedly chanted "how can the emperor imagine I could have broken my vows when it was I who performed the sacred rites to bring him victories and triumphs!" Pliny states that it is unknown whether she uttered these words out of contempt for Domitian or to try to incur his mercy. When she was descending into the underground chamber within which she was to be buried, her stola was caught and the executioner ("carnifex"), presumably Domitian, attempted to free her, but she—out of disgust—pushed away his touch.
Her supposed lover, a Roman equestrian named Celer, also protested his innocence, even as he was being publicly beaten to death in the Comitium with sticks. In Pliny's account, Domitian then sought to prosecute an individual named Licinianus, whom he accused of having hidden one of Cornelia's freedwomen in his house. Licinianus was then supposedly advised by others to admit guilt so as to as to avoid public execution in the same manner as Celer. He heeded this advice, and sent a messenger named Herennius Senecio to inform Domitian of his confession. Afterwards, Domitian granted Licinianus the lighter sentence of exile, and he was permitted to keep any items he could manage to remove from his house before his property was confiscated. Pliny further writes that, eventually, under the reign of Emperor Nerva, Licinianus was permitted to travel to Sicily, where he found work as a teacher.
She has been identified with the "Cornelia of the family of Cossi" ("Cornelia ex familia Cossorum capta est") mentioned by the 1st-century historian Tacitus as a replacement for the Vestal virgin Laelia in the year 62 CE. If these two Vestals were the same person, it would indicate that she was aged between 32 and 39 years old at the time of her execution, for Vestal Virgins were—according to the 2nd-century author Aulus Gellius—recruited when aged between 6 and 10 years old. According to the classicist Jakub Pigoń, five of the six members of the college of Vestals during the early reign of Domitian are known: Cornelia, Varronilla, Licinia Praetextata, and two sisters Oculata. If the Cornelia mentioned by Tacitus were not to be identified with the Cornelia described by Pliny and Suetonius, then it would imply that she was the sixth unknown Vestal, and therefore that there were two separate individuals both named Cornelia serving at the same time. Alternatively, it is possible that the Cornelia mentioned by Tacitus had already died by the time of the Cornelia referred to by Suetonius and Pliny, though one inscription dating to the second half of the 1st-century BCE mentions a living Vestal named Cornelia, who was the daughter of Cossus Gaetulicus, which implies that that subject of Tacitus's account did not die young. Moreover, Pigoń argues that Tacitus had a tendency to mention relatively insignificant details of a notable figure's early life should they happen to have been involved in some other event before they were able to accomplish whatever it was the rendered themselves so significant. Thus, Tacitus's mention of Cornelia could be understood along the same lines—it is a seemingly irrelevant detail only given weight because of the Roman audience's familiarity with her later execution.