(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 86,493 | 12,471,646 | .69% | Bangkok (Archdiocese) | 2004 | ap2005 |
| 2 | 6,682 | 9,015,380 | .07% | Surat Thani | 2004 | ap2005 |
| 3 | 10,878 | 8,358,639 | .13% | Nakhon Sawan | 2004 | ap2005 |
| 4 | 25,571 | 7,921,032 | .32% | Ubon Ratchathani | 2004 | ap2005 |
| 5 | 41,944 | 5,824,935 | .72% | Chiang Mai | 2004 | ap2005 |
| 6 | 16,359 | 5,318,718 | .31% | Udon Thani | 2004 | ap2005 |
| 7 | 5,464 | 5,198,400 | .11% | Nakhon Ratchasima | 2004 | ap2005 |
| 8 | 38,880 | 4,333,797 | .90% | Chanthaburi | 2004 | ap2005 |
| 9 | 50,008 | 3,157,780 | 1.58% | Thare and Nonseng (Archdiocese) | 2004 | ap2005 |
| 10 | 15,730 | 2,327,381 | .68% | Ratchaburi | 2004 | ap2005 |
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