Predominantly Christian, the population of St. John's was once divided along sectarian (Catholic/Protestant) lines. In recent years, this sectarianism has declined significantly, and is no longer a commonly acknowledged facet of life in St. John's. St. John's is the seat of the Roman Catholic Archbishop of St. John's, and the Anglican Bishop of Eastern Newfoundland and Labrador. All major Christian sects showed a decline from 2001–2011 with a large increase in those with no religion from 3.9% to 11.1%.

What is the largest religion in St. John's?