(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 500,000 | 25,290,000 | 1.98% | Trasfigurazione a Novosibirsk | 2004 | ap2005 |
| 2 | 200,000 | 58,820,000 | .34% | Madre di Dio a Mosca (Archdiocese) | 2004 | ap2005 |
| 3 | 52,000 | 15,500,000 | .34% | San Giuseppe a Irkutsk | 2004 | ap2005 |
| 4 | 35,000 | 47,000,000 | .07% | San Clemente a Saratov | 2004 | ap2005 |
| 5 | 2,100 | 515,000 | .41% | Yuzhno Sakhalinsk (Prefecture Apostolic) | 2004 | ap2005 |
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