Theodora (c. 815 – after 867) is a Byzantine Empress as the spouse of the Byzantine emperor Theophilos, and regent of her son, Michael III, from Theophilos' death in 842 to 855.

For her restoration of the veneration of icons, which ends the Byzantine Iconoclasm, she is venerated as a saint in the Eastern Orthodox Church; her Feast Day is February 11.

She is the patron Saint of Churches.