(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 231,205 | 679,113 | 34.05% | Chilaw | 2004 | ap2005 |
| 2 | 73,977 | 219,633 | 33.68% | Mannar | 2004 | ap2005 |
| 3 | 648,184 | 5,522,956 | 11.74% | Colombo (Archdiocese) | 2004 | ap2005 |
| 4 | 166,329 | 1,625,925 | 10.23% | Jaffna | 2004 | ap2005 |
| 5 | 62,078 | 1,514,336 | 4.10% | Trincomalee-Batticaloa | 2004 | ap2005 |
| 6 | 48,967 | 1,505,866 | 3.25% | Kurunegala | 2004 | ap2005 |
| 7 | 75,435 | 2,414,973 | 3.12% | Kandy | 2004 | ap2005 |
| 8 | 21,985 | 1,614,000 | 1.36% | Badulla | 2004 | ap2005 |
| 9 | 23,812 | 1,797,355 | 1.32% | Ratnapura | 2004 | ap2005 |
| 10 | 9,855 | 1,105,663 | .89% | Anuradhapura | 2004 | ap2005 |
| 11 | 8,100 | 2,210,486 | .37% | Galle | 2004 | ap2005 |
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