The diocese includes parishes in the counties of Østfold and Akershus, excluding Asker and Bærum.

[1] Fredrikstad Cathedral was designed by architect Waldemar F. Luhr and built in 1880.

When Borg diocese was created in 1968, the cathedral changed its name.

The richly decorated pulpit and the colourful wooden altar piece, dating back to 1897, were the work of Wilhelm Peters and represents Jesus healing the blind man.

[2] The Diocese of Borg is divided into eight deaneries (Norwegian: Prosti) spread out over Viken county.