The architecture is mainly Norman, following a rebuilding in the 12th century. With Durham and Ely Cathedrals, it is one of the most important 12th-century buildings in England to have remained largely intact, despite extensions and restoration.

Peterborough Cathedral is known for its imposing Early English Gothic West Front (façade) which, with its three enormous arches, is without architectural precedent and with no direct successor. The appearance is slightly asymmetrical, as one of the two towers that rise from behind the façade was never completed (the tower on the right as one faces the building), but this is only visible from a distance, while the effect of the West Front upon entering the Cathedral Close is overwhelming