| | Rolling Hills Estates, CA | Mountain Brook, AL | United States |
| Percent Religious | 53.4% | 84.1% | 49.4% |
| Baptist | 2.0% | 40.2% | 8.2% |
| Episcopalian | 0.4% | 2.1% | 0.6% |
| Catholic | 37.0% | 8.6% | 19.7% |
| Church of Jesus Christ | 1.6% | 0.7% | 2.1% |
| Lutheran | 0.5% | 0.5% | 2.4% |
| Pentecostal | 1.8% | 4.9% | 1.9% |
| Methodist | 1.2% | 9.4% | 4.0% |
| Presbyterian | 0.8% | 2.8% | 1.7% |
| Other Christian | 5.2% | 13.6% | 6.7% |
| Judaism | 1.1% | 0.6% | 0.7% |
| Eastern | 1.1% | 0.0% | 0.5% |
| Islam | 0.7% | 0.5% | 0.9% |