Oakley, California's estimated population is 42,129 according to the most recent United States census estimates. Oakley, California is the 201st largest city in California based on official 2017 estimates from the US Census Bureau.
The population density is 2655.84 people/mi² (1025.42 people/km²).
The overall median age is 34.3 years, 34.1 years for males, and 34.6 years for females. For every 100 females there are 100.5 males.
Based on data from the American Community Survey, in 2017 there were households in the city, with an average size of 3.41 people per household. The homeowner vacancy rate was %, with a median rent of $/month. The median house has rooms, and has a value of $.
The median income for households in Oakley, California is $89,392, while the mean household income is $99,481.
According to the most recent ACS, the racial composition of Oakley Ca was:
| Year | Population | Growth | Annual Growth Rate |
| 2018 | 42,129 | 518 | 1.24% |
| 2017 | 41,611 | 931 | 2.29% |
| 2016 | 40,680 | 953 | 2.40% |
| 2015 | 39,727 | 579 | 1.48% |
| 2014 | 39,148 | 984 | 2.58% |
| 2013 | 38,164 | 968 | 2.60% |
| 2012 | 37,196 | 590 | 1.61% |
| 2011 | 36,606 | 931 | 2.61% |
| 2010 | 35,675 | 10,056 | 3.37% |
| 2000 | 25,619 | 7,245 | 3.38% |
| 1990 | 18,374 | 15,558 | 20.63% |
| 1980 | 2,816 | 1,510 | 7.99% |
| 1970 | 1,306 | 0.00% |
| Race | Population |
| White | 24,715 |
| Some Other Race | 5,039 |
| Black or African American | 3,582 |
| Asian | 3,103 |
| Two or More Races | 2,878 |
| American Indian and Alaska Native | 474 |
| Native Hawaiian and Other Pacific Islander | 159 |
| Type | Count | Average Size | Owned |
| All | 11,671 | 3.41 | 75.3 |
| Married | 7,031 | 3.91 | 85 |
| Non Family | 2,327 | 1.37 | 63.1 |
| Female | 1,539 | 4.14 | 54.5 |
| Male | 774 | 3.62 | 64.7 |
| Education Attained | Count | Percentage |
| Less Than 9th Grade | 1,604 | 6.55% |
| 9th to 12th Grade | 1,527 | 6.23% |
| High School Graduate | 6,929 | 28.27% |
| Some College | 7,263 | 29.64% |
| Associates Degree | 2,532 | 10.33% |
| Bachelors Degree | 3,343 | 13.64% |
| Graduate Degree | 1,308 | 5.34% |
| Name | Total | High School | Bachelors |
| White | 11,952 | 11,248 | 2,168 |
| Hispanic | 7,472 | 5,431 | 782 |
| Other Race | 2,577 | 1,931 | 119 |
| Asian | 2,216 | 2,095 | 913 |
| Black | 2,004 | 1,888 | 672 |
| Multiple Races | 963 | 862 | 178 |
| Native American | 280 | 164 | |
| Islander | 89 | 43 |
The highest rate of high school graduation is among asian people with a rate of 94.54%.
The highest rate of bachelors degrees is among asian people with a rate of 41.20%.
68.15% of Oakley Ca residents speak only English, while 31.85% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 23.45% of the population.
| Name | Total | In Poverty | Poverty Rate |
| White | 17,031 | 1,064 | 6.25% |
| Hispanic | 13,918 | 882 | 6.34% |
| Black | 3,536 | 507 | 14.34% |
| Other | 5,028 | 368 | 7.32% |
| Multiple | 2,776 | 348 | 12.54% |
| Asian | 3,099 | 185 | 5.97% |
| Islander | 159 | 29 | 18.24% |
| Native | 465 | 25 | 5.38% |
7.48%
Overall Poverty Rate
6.61%
Male Poverty Rate
8.35%
Female Poverty Rate
The race most likely to be in poverty in Oakley Ca is Islander, with 18.24% below the poverty level.
The race least likely to be in poverty in Oakley Ca is Native, with 5.38% below the poverty level.
The poverty rate among those that worked full-time for the past 12 months was 1.61%. Among those working part-time, it was 10.04%, and for those that did not work, the poverty rate was 15.35%.
50.9%
Overall Marriage Rate
50.8%
Male Marriage Rate
51.0%
Female Marriage Rate
The age group where males are most likely to be married is 35-44, while the female age group most likely to be married is 35-44.
| Name | Veterans | % of Total |
| White | 1,251 | 6.63% |
| Hispanic | 220 | 2.45% |
| Black | 174 | 7.10% |
| 2 or More | 107 | 8.07% |
| Asian | 93 | 3.64% |
| Hawaiian | 29 | 18.24% |
| Other | 25 | 0.81% |
| Indian | 19 | 5.11% |
10.56%
Veteran Poverty Rate
26.59%
Veteran Disability Rate
66.9%
Labor Force Participation
62.3%
Employment Rate
6.8%
Unemployment Rate
Non citizens include legal permanent residents (green card holders), international students, temporary workers, humanitarian migrants, and illegal immigrants.
80.93%
Native Born
19.07%
Foreign Born
9.51%
Non Citizen
80.93% of Oakley Ca residents were born in the United States, with 67.95% having been born in California. 9.51% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Latin America.