Galeria Valeria (died 315) was the daughter of Roman Emperor Diocletian and wife of his co-emperor Galerius.
Born as Valeria to Diocletian and Prisca, she married Galerius in 293, when her father elevated him to the position of Caesar. This marriage was clearly organized to strengthen the bonds between the two emperors.
Galeria was raised to the title of Augusta and Mater Castrorum in November 308. Since Galerius fathered no child with her, Galeria adopted her husband's illegittimate son, Candidianus, as her own.
When Galerius died, in 311, Licinius was entrusted with the care of Valeria and her mother Prisca. The two women, however, fled from Licinius to Maximinus Daia, whose daughter was betrothed to Candidianus. After a short time, Valeria refused the marriage proposal of Maximinus, who arrested and confined her in Syria and confiscated her properties. At the death of Maximinus, Licinius ordered the death of both women. Valeria fled, hiding for a year, until she was found in Thessaloniki. She was captured by the mob, beheaded in the central square of the city, and her body thrown in the sea.
Galeria was sympathetic towards Christians, while Galerius persecuted them. She was canonized as a Christian saint with her mother (see Saint Alexandra).
