Roman Catholicism and the Aglipayan Church are the two major religions in the province.

Among the major Roman Catholic churches in Ilocos Norte include:
Paoay Church — named a UNESCO World Heritage Site in 1993.

St. William's Cathedral in Laoag — known for its Sinking Bell Tower
Santa Monica Church in Sarrat — documented to be the biggest church in the Ilocos Region.

Bacarra Church — destroyed during an intensity VII (on the Rossi-Forel scale) earthquake on August 17, 1983, reconstructed and re-inaugurated in 1984.

Ilocos Norte is the home of the Aglipay Shrine (Aglipayan Church) where the church's first supreme leader was buried.
There are also increasing members of Jehovah's Witnesses.
There are also minor but steadily increasing members of Iglesia ni Cristo.
Islam is also practiced by Mindanaoan traders and immigrants.
Roman Catholicism and the Aglipayan Church are the two major religions in the province.
Among the major Roman Catholic churches in Ilocos Norte include:
Paoay Church — named a UNESCO World Heritage Site in 1993.
St. William's Cathedral in Laoag — known for its Sinking Bell Tower
Santa Monica Church in Sarrat — documented to be the biggest church in the Ilocos Region.
Bacarra Church — destroyed during an intensity VII (on the Rossi-Forel scale) earthquake on August 17, 1983, reconstructed and re-inaugurated in 1984.
Ilocos Norte is the home of the Aglipay Shrine (Aglipayan Church) where the church's first supreme leader was buried. There are also increasing members of Jehovah's Witnesses. There are also minor but steadily increasing members of Iglesia ni Cristo. Islam is also practiced by Mindanaoan traders and immigrants.
Ilocos Norte