Viktor of Xanten was a 4th-century military officer and martyr recognized as a saint by both the Eastern Orthodox and Roman Catholic churches. Serving as a leader within a cohort of the Theban Legion, he was reportedly executed in the amphitheater at Castra Vetera, the location of modern-day Xanten. His death occurred during the persecutions led by Emperor Maximian after he refused to participate in sacrifices to Roman deities. He is often associated with other figures, such as Ursus of Solothurn and Gereon of Cologne.