Domitia Longina was born sometime between 50 and 55, as the youngest daughter of Gnaeus Domitius Corbulo and Cassia Longina. Through her mother (a great-great-great granddaughter of Augustus), Domitia Longina was a direct descendant of Augustus Caesar and one of the last remaining members of the Julian lineage. Her paternal aunt was Milonia Caesonia, Roman Empress to Caligula. Her elder sister, Domitia, married the senator Lucius Annius Vinicianus. Domitia's father Corbulo had been one of Rome's most respected Senators and generals, serving as consul under Caligula, and conducting military campaigns in Germania and Parthia under Claudius and Nero.
Little is known about the life of Domitia before her marriage to Domitian, but sometime before 70, Domitia was married to Lucius Aelius Plautius Lamia Aelianus, a man of senatorial rank.
Domitia divorced her first husband Lucius Aelius Lamia in order to marry Domitian in 71. The marriage produced only one son, whose early death is believed to have been the cause of temporary rift between Domitia and her husband in 83. She became Empress of Rome upon Domitian's accession in 81, and remained so until his assassination in 96. She is believed to have died sometime between 126 and 130.