| | Ajo, AZ | Rio Rico, AZ | United States |
| Population | 2,944 | 20,914 | 329,725,481 |
| Female Population | 51.4% | 52.3% | 50.5% |
| Male Population | 48.6% | 47.7% | 49.5% |
| Median Age | 58.6 | 34.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,206 | 19,270 | 309,327,143 |
| Population - 2000 | 3,705 | 10,987 | 285,036,114 |
| Population - 1990 | 2,919 | 4,505 | 251,960,433 |
| Pop. 2000 to Now | 0.0% | 73.1% | 15.6% |
| Pop. 1990 to Now | 26.9% | 322.2% | 30.8% |
| space4 | | | |
| Population Density | 88.3 | 335.9 | 93.4 |
| Land Area | 33.3 | 62.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Ajo, AZ | Rio Rico, AZ | United States |
| Age 0 to 4 | 2.2% | 8.3% | 5.9% |
| Age 5 to 9 | 3.3% | 9.5% | 6.1% |
| Age 10 to 14 | 3.1% | 8.3% | 6.6% |
| Age 15 to 17 | 2.4% | 4.2% | 3.9% |
| Age 18 to 20 | 6.7% | 3.2% | 4.0% |
| Age 21 to 24 | 3.7% | 7.1% | 5.2% |
| Age 25 to 34 | 8.3% | 11.6% | 13.8% |
| Age 35 to 44 | 13.4% | 12.3% | 12.9% |
| Age 45 to 54 | 2.4% | 11.3% | 12.6% |
| Age 55 to 59 | 7.1% | 6.2% | 6.7% |
| Age 60 to 64 | 11.0% | 7.0% | 6.3% |
| Age 65 to 74 | 20.0% | 7.0% | 9.6% |
| Age 75 to 84 | 11.0% | 3.3% | 4.5% |
| Age 85 and over | 5.6% | 0.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Ajo, AZ | Rio Rico, AZ | United States |
| White | 48.1% | 11.1% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.6% | 0.0% | 5.6% |
| Native American | 2.6% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.3% | 0.0% | 3.2% |
| Hispanic | 46.4% | 88.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Ajo, AZ | Rio Rico, AZ | United States |
| Married Population | 44.7% | 53.4% | 49.8% |
| Currently Married | 43.0% | 52.3% | 48.0% |
| Married but Separated | 1.7% | 1.2% | 1.8% |
| Single Population | 55.3% | 46.6% | 50.2% |
| Never Married | 30.4% | 32.3% | 33.8% |
| Divorced | 16.2% | 12.0% | 10.8% |
| Widowed | 8.8% | 2.3% | 5.6% |
| space5 | | | |
| Household Size | 2.10 | 3.16 | 2.60 |
| Households | 1,397 | 6,620 | 124,010,992 |
| Family Households | 753 | 5,404 | 80,755,759 |
| Married couple, w/children | 19.8% | 39.2% | 30.5% |
| Married couple, no children | 51.5% | 30.2% | 42.9% |
| Non Family Households | 644 | 1,216 | 43,255,233 |
| Single householder, w/children | 4.1% | 17.5% | 15.8% |
| Single householder, no children | 24.6% | 13.2% | 10.8% |