New Haven is a predominantly Roman Catholic city, as the city's Dominican, Irish, Italian, Mexican, Ecuadorian, and Puerto Rican populations are overwhelmingly Catholic. The city is part of the Archdiocese of Hartford. Jews also make up a considerable portion of the population, as do Black Baptists. There is a growing number of (mostly Puerto Rican) Pentecostals as well. There are churches for all major branches of Christianity within the city, multiple store-front churches, ministries (especially in working-class Latino and Black neighborhoods), a mosque, many synagogues (including two yeshivas), and other places of worship; the level of religious diversity in the city is high.

What is the most prominent religion in New Haven?