The 10 Largest Catholic Dioceses in the United States by Population (2020)

America's Largest Catholic Communities

The landscape of American Catholicism is defined by a handful of massive metropolitan archdioceses and dioceses. Based on 2020 data, here are the ten largest by registered Catholic population.

1. Archdiocese of Los Angeles (California) – 4,930,000
2. Archdiocese of New York (New York) – 2,828,000
3. Diocese of Brooklyn (New York) – 1,558,000
4. Archdiocese of Chicago (Illinois) – 1,473,000
5. Archdiocese of Philadelphia (Pennsylvania) – 1,382,000
6. Archdiocese of Boston (Massachusetts) – 1,331,000
7. Diocese of Orange (California) – 1,313,000
8. Archdiocese of Newark (New Jersey) – 1,299,000
9. Archdiocese of Cincinnati (Ohio) – 1,194,000
10. Diocese of Dallas (Texas) – 1,189,000

These jurisdictions, concentrated in major urban corridors, reflect historic immigration patterns and the continued growth of the Church in the Sun Belt.