(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 1,455,983 | 1,644,956 | 88.51% | Zagreb (Archdiocese) | 2004 | ap2005 |
| 2 | 447,910 | 1,426,818 | 31.39% | Djakovo o Bosna i Srijem | 2004 | ap2005 |
| 3 | 428,382 | 464,329 | 92.26% | Split-Makarska (Archdiocese) | 2004 | ap2005 |
| 4 | 373,874 | 393,000 | 95.13% | Varaždin | 2004 | ap2005 |
| 5 | 286,796 | 318,678 | 90.00% | Požega | 2004 | ap2005 |
| 6 | 213,650 | 266,800 | 80.08% | Rijeka (Archdiocese) | 2004 | ap2005 |
| 7 | 168,699 | 208,717 | 80.83% | Porec i Pula | 2004 | ap2005 |
| 8 | 158,344 | 164,160 | 96.46% | Zadar (Archdiocese) | 2004 | ap2005 |
| 9 | 110,500 | 121,600 | 90.87% | Šibenik | 2004 | ap2005 |
| 10 | 81,000 | 102,000 | 79.41% | Gospic-Senj | 2004 | ap2005 |
| 11 | 75,400 | 87,900 | 85.78% | Dubrovnik | 2004 | ap2005 |
| 12 | 36,824 | 41,303 | 89.16% | Krk | 2004 | ap2005 |
| 13 | 22,781 | 25,665 | 88.76% | Hvar (-Brac e Vis) | 2004 | ap2005 |
| 14 | 15,311 | Križevci (Byzantine) | 2004 | ap2005 |
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