Theophanu (, Theophano Skleraina; c. 955June 15, 991), also spelled Theophania (Θεοφάνια), Theophana or Theophano, was the niece of the Byzantine Emperor John I Tzimiskes. By her marriage with Holy Roman Emperor Otto II, she was Empress consort of the Holy Roman Empire and held regency as Empress dowager upon her husband's death in 983. Her name is derived from Medieval Greek Theophaneia (Θεοφάνεια), "appearance of God" (Theophany).