(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 113,833 | 123,185 | 92.41% | Bloemfontein (Archdiocese) | 2004 | ap2005 |
| 2 | 60,501 | 331,984 | 18.22% | Keimoes-Upington | 2004 | ap2005 |
| 3 | 284,400 | 1,819,400 | 15.63% | Mariannhill | 2004 | ap2005 |
| 4 | 700,000 | 6,000,000 | 11.67% | Johannesburg | 2004 | ap2005 |
| 5 | 86,512 | 940,153 | 9.20% | Kroonstad | 2004 | ap2005 |
| 6 | 75,566 | 935,912 | 8.07% | Bethlehem | 2004 | ap2005 |
| 7 | 41,260 | 530,000 | 7.78% | Aliwal | 2004 | ap2005 |
| 8 | 141,363 | 1,894,680 | 7.46% | Umzimkulu | 2004 | ap2005 |
| 9 | 103,466 | 1,500,000 | 6.90% | Klerksdorp | 2004 | ap2005 |
| 10 | 205,387 | 3,000,000 | 6.85% | Durban (Archdiocese) | 2004 | ap2005 |
| 11 | 117,335 | 1,740,000 | 6.74% | Kimberley | 2004 | ap2005 |
| 12 | 205,679 | 3,539,306 | 5.81% | Cape Town (Archdiocese) | 2004 | ap2005 |
| 13 | 72,000 | 1,300,000 | 5.54% | Kokstad | 2004 | ap2005 |
| 14 | 43,500 | 980,000 | 4.44% | Rustenburg | 2004 | ap2005 |
| 15 | 75,375 | 1,711,715 | 4.40% | Dundee | 2004 | ap2005 |
| 16 | 103,278 | 2,528,000 | 4.09% | Witbank | 2004 | ap2005 |
| 17 | 68,198 | 1,717,676 | 3.97% | Umtata | 2004 | ap2005 |
| 18 | 186,383 | 4,705,000 | 3.96% | Pretoria (Archdiocese) | 2004 | ap2005 |
| 19 | 23,054 | 609,180 | 3.78% | Ingwavuma (Vicariate Apostolic) | 2004 | ap2005 |
| 20 | 81,000 | 2,200,600 | 3.68% | Eshowe | 2004 | ap2005 |
| 21 | 98,800 | 2,698,800 | 3.66% | Port Elizabeth | 2004 | ap2005 |
| 22 | 86,268 | 2,500,000 | 3.45% | Pietersburg | 2004 | ap2005 |
| 23 | 5,620 | 164,000 | 3.43% | De Aar | 2004 | ap2005 |
| 24 | 56,000 | 2,110,000 | 2.65% | Queenstown | 2004 | ap2005 |
| 25 | 26,344 | 997,920 | 2.64% | Oudtshoorn | 2004 | ap2005 |
| 26 | 49,543 | 2,200,000 | 2.25% | Tzaneen | 2004 | ap2005 |
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