St Albans Cathedral, officially the Cathedral and Abbey Church of St Alban is a Church of England cathedral in St Albans, England.

St Albans Cathedral stands near the supposed site of Alban's martyrdom. Alban lived in Verulamium, some time during the 3rd or 4th centuries. The legend proceeds with Alban meeting a Christian priest (known as Amphibalus) fleeing from persecutors, and sheltering him in his house for a number of days. Alban was so impressed with the priest's faith and piety that he soon converted to Christianity. Eventually Roman soldiers came to seize the priest, but Alban put on his cloak and presented himself to the soldiers in place of his guest. Alban was brought before a judge and was sentenced to beheading.

Much of its architecture dates from Norman times. Much of the current layout and proportions of the structure date from the first Norman abbot, Paul of Caen (1077–1093).

Building work started in the year of Abbot Paul's arrival. The design and construction were overseen by the Norman Robert the Mason. The plan has very limited Anglo-Saxon elements and is clearly influenced by the French work at Cluny, Bernay and Caen.