Rochester Cathedral is a Norman church in Rochester, Kent. The bishopric is one of the oldest in England, second only to that of Canterbury. It was founded by Justus, one of the missionaries who accompanied Saint Augustine to convert the pagan English to Christianity in the early 7th century. Justus was given permission by King Ethelbert of Kent to establish a church of St Andrew the Apostle on the site of the present cathedral, which was made the home of a bishopric. The first Bishop of Rochester being Justus himself, with subsequent bishops being recruited from among the Christianised English.

When William of Normandy conquered England in 1066, he gave the church and its estates to his brother, Odo of Bayeux. The church was reduced to near-destitution, a situation only remedied in 1082 when Lanfranc, Archbishop of Canterbury visited and restored some of its lands and staff. Gundulf , the Norman Bishop of Rochester, also played a very active role; a talented architect himself, the bishop commissioned and probably had a major part in designing a new cathedral to replace Justus' church.

The present building is widely regarded as one of the finest Norman cathedrals in the country, with a particularly fine doorway at its western (main) entrance. The tympanum depicts Christ sitting in glory in the centre, with Justus and Ethelbert flanking him on either side of the doorway.

After Gundulf's death, the cathedral had a somewhat chequered history. It was badly damaged by fires in 1137 and 1179. It was then looted in 1215 by the forces of King John and again in 1264 by Simon de Montfort, during sieges of the city. It suffered a steep decline after the dissolution of the monasteries in the 16th century, during which time its estates were confiscated by the Crown, and became dilapidated and disreputable. Samuel Pepys, the diarist, dismissed it as a "shabby place". It underwent some restoration work of mixed success during the 19th century before Sir Giles Gilbert Scott took on the task in 1880, renovating the cathedral and restoring it to a reasonable facsimile of its original 11th century condition.