(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 2,852,257 | 3,169,175 | 90.00% | Lima (Archdiocese) | 2004 | ap2005 |
| 2 | 2,313,000 | 2,721,000 | 85.01% | Lurín | 2004 | ap2005 |
| 3 | 2,000,000 | 2,300,000 | 86.96% | Carabayllo | 2004 | ap2005 |
| 4 | 1,509,405 | 1,760,005 | 85.76% | Chosica | 2004 | ap2005 |
| 5 | 1,350,000 | 1,400,000 | 96.43% | Cuzco (Archdiocese) | 2004 | ap2005 |
| 6 | 1,250,448 | 1,302,551 | 96.00% | Piura (Archdiocese) | 2004 | ap2005 |
| 7 | 1,083,908 | 1,188,219 | 91.22% | Chiclayo | 2004 | ap2005 |
| 8 | 1,078,548 | 1,315,302 | 82.00% | Trujillo (Archdiocese) | 2004 | ap2005 |
| 9 | 836,035 | 950,040 | 88.00% | Callao | 2004 | ap2005 |
| 10 | 835,223 | 928,025 | 90.00% | Arequipa (Archdiocese) | 2004 | ap2005 |
| 11 | 823,206 | 925,230 | 88.97% | Tacna y Moquegua | 2004 | ap2005 |
| 12 | 780,330 | 815,435 | 95.69% | Cajamarca | 2004 | ap2005 |
| 13 | 770,200 | 951,400 | 80.95% | Iquitos (Vicariate Apostolic) | 2004 | ap2005 |
| 14 | 740,523 | 822,804 | 90.00% | Huánuco | 2004 | ap2005 |
| 15 | 728,867 | 792,505 | 91.97% | Huancayo (Archdiocese) | 2004 | ap2005 |
| 16 | 720,000 | 730,000 | 98.63% | Ica | 2004 | ap2005 |
| 17 | 570,000 | 655,000 | 87.02% | Chimbote | 2004 | ap2005 |
| 18 | 553,785 | 692,232 | 80.00% | Moyobamba (Territorial Prelature) | 2004 | ap2005 |
| 19 | 522,575 | 614,795 | 85.00% | Tarma | 2004 | ap2005 |
| 20 | 515,182 | 606,096 | 85.00% | Puno | 2004 | ap2005 |
| 21 | 440,000 | 460,000 | 95.65% | Huacho | 2004 | ap2005 |
| 22 | 419,000 | 485,000 | 86.39% | Chulucanas | 2004 | ap2005 |
| 23 | 406,709 | 444,829 | 91.43% | Huancavélica | 2004 | ap2005 |
| 24 | 400,000 | 450,000 | 88.89% | Juli (Territorial Prelature) | 2004 | ap2005 |
| 25 | 377,912 | 490,795 | 77.00% | Pucallpa (Vicariate Apostolic) | 2004 | ap2005 |
| 26 | 373,800 | 480,257 | 77.83% | Jaén en Peru o San Francisco Javier (Vicariate Apostolic) | 2004 | ap2005 |
| 27 | 350,000 | 390,000 | 89.74% | Huaraz | 2004 | ap2005 |
| 28 | 316,000 | 338,000 | 93.49% | Chota (Territorial Prelature) | 2004 | ap2005 |
| 29 | 307,570 | 349,512 | 88.00% | Chachapoyas | 2004 | ap2005 |
| 30 | 303,000 | 328,000 | 92.38% | Abancay | 2004 | ap2005 |
| 31 | 300,000 | 400,000 | 75.00% | San Ramón (Vicariate Apostolic) | 2004 | ap2005 |
| 32 | 299,646 | 499,410 | 60.00% | Ayacucho o Huamanga (Archdiocese) | 2004 | ap2005 |
| 33 | 296,500 | 306,000 | 96.90% | Huarí (Territorial Prelature) | 2004 | ap2005 |
| 34 | 234,000 | 274,000 | 85.40% | Sicuani (Territorial Prelature) | 2004 | ap2005 |
| 35 | 217,000 | 258,000 | 84.11% | Puerto Maldonado (Vicariate Apostolic) | 2004 | ap2005 |
| 36 | 208,088 | 214,523 | 97.00% | Yauyos (Territorial Prelature) | 2004 | ap2005 |
| 37 | 201,500 | 235,000 | 85.74% | Yurimaguas (Vicariate Apostolic) | 2004 | ap2005 |
| 38 | 175,800 | 179,300 | 98.05% | Ayaviri (Territorial Prelature) | 2004 | ap2005 |
| 39 | 149,500 | 230,000 | 65.00% | Huamachuco (Territorial Prelature) | 2004 | ap2005 |
| 40 | 135,647 | 138,416 | 98.00% | Chuquibamba (Territorial Prelature) | 2004 | ap2005 |
| 41 | 123,392 | 164,680 | 74.93% | San José de Amazonas (Vicariate Apostolic) | 2004 | ap2005 |
| 42 | 120,000 | 135,000 | 88.89% | Requena (Vicariate Apostolic) | 2004 | ap2005 |
| 43 | 105,000 | 115,000 | 91.30% | Caravelí (Territorial Prelature) | 2004 | ap2005 |
| 44 | 80,000 | 83,000 | 96.39% | Chuquibambilla (Territorial Prelature) | 2004 | ap2005 |
|