Perfectus (Latin Perfectus, 'the Perfect') was a Mozarabic Catholic priest of Córdoba — a member of the Catholic community that had survived the Umayyad conquest of Visigothic Spain in 711, retaining their Catholic Latin liturgy and faith under increasing Islamic social, fiscal, and legal pressure.
His martyrdom — the opening event of the 'Córdoba martyr-cycle' of 850–859 documented by St. Eulogius of Córdoba — was triggered by a public confrontation in the marketplace of Córdoba: a group of Muslim Cordobans asked the Christian priest Perfectus to compare Christ and Muhammad. Perfectus, after first asking and receiving their pledge that he could speak freely without legal consequence, gave the Catholic theological answer — Christ as God-incarnate, Muhammad as a false prophet — at which the Muslims, ignoring their pledge, denounced Perfectus to the Umayyad qadi (Islamic judge) for blasphemy against the Prophet.
Imprisoned for several months and given multiple opportunities to retract, Perfectus instead amplified his condemnation of Muhammad as a false prophet. On the Muslim feast of the Eid al-Fitr (end of Ramadan), April 18, 850, he was beheaded by Umayyad order in the central marketplace of Córdoba — the opening martyrdom of the Córdoba martyr-cycle.
Over the next nine years (850–859), some 48 documented Mozarabic Catholic martyrs would follow Perfectus into martyrdom — the Catholic protest-witness against the accelerating Islamization of al-Andalus. The cycle was documented by St. Eulogius of Córdoba in his Memoriale Sanctorum and Liber Apologeticus Martyrum (the Catholic primary text of Christian-Islamic martyrdom literature).