Annia Aurelia Fadilla, most commonly known as Fadilla (159-died after 211) was an influential Roman Princess and was one of the daughters born to Roman Emperor Marcus Aurelius and Roman Empress Faustina the Younger. She was a sister to Roman Empress Lucilla and Roman Emperor Commodus. Fadilla was named in honor of her late maternal aunt Aurelia Fadilla. The cognomen Fadilla, was the cognomen of the mother and a half-sister of the previous Roman Emperor Antoninus Pius. Her maternal grandparents were Roman Emperor Antoninus Pius and Roman Empress Faustina the Elder and her paternal grandparents were Domitia Lucilla and praetor Marcus Annius Verus.
Fadilla was born and raised in Rome. During the reign of her father, she married the Roman senator, who served later twice as consul and as Augur, Marcus Peducaeus Plautius Quintillus, a nephew of Roman Emperor Lucius Verus who co-ruled with her father from 161–169 and through adoption was her uncle. The mother Plautius Quintillus was Ceionia Fabia, sister of Lucius Verus. Fadilla bore Marcus Peducaeus Plautius Quintillus two children: son (Plautius) Quintillus and a daughter Plautia Servilla.
When her father died in 180, her remaining brother Commodus succeeded him as Roman Emperor. During Commodus' reign, Fadilla and her family lived in a private palace on Capitoline Hill in Rome which was later bestowed by the later Roman Emperor Elagabalus (218–222) as one of his mother's favorite residences. Her husband became one of Commodus' main advisers.