Domitia Longina was a Roman matrona that lived in the 1st century. She was daughter of the general Gnaeus Domitius Corbulo and his wife, Cassia Longina.
In 70, Domitian was married to Lucius Aelius Lamia, but she attracted the attention of Domitian, son of emperor Vespasian. Shortly afterwards she was took from her husband and remarried with the future emperor. They had a son in the next year and a daughter in 74, both died young. Domitian was very fond of his wife and carried her in all his travels. Nevertheless, he was also seen often in the company of other women and kept an enormous amount of lovers. He did not, however, tolerate the same kind of liberties from his wife. In 83, Domitia Longina's affair with the actor Paris was disclosed. Paris was executed and Domitia received her letter of divorce from Domitian. She was exiled, but remained close to Roman politics and to Domitian. In 96, her actions were decisive for the success of the plot to murder the unpopular emperor. Domitia died peacefully in 126 AD.
Domitia Longina appears frequently in coins minted during Domitian's reign.