Demographics
San Luis Obispo County is home to approximately 280,000 people. Overall, the County population is older, less ethnically and racially diverse, and more highly educated than California's population as a whole.
Geography
San Luis Obispo County is located along the Pacific Coast, approximately 200 miles north of Los Angeles and 235 miles south of San Francisco. It is one of California’s 58 counties and is considered part of the Central Coast region of California.
Where We Live
The county includes 7 cities and 14 community service districts, though most of the county’s 3,326 square miles are unincorporated. The majority of residents live along the coast or along the corridor of Highway 101. SLO County population per square mile is a low 85.6 compared to 253.7 for the state.
The eastern region of the county is sparsely populated with vast areas of agricultural and undeveloped government lands between small, unincorporated towns. Key industries in the county include tourism, education, energy, agriculture and government.
85.6
Population per square mile in SLO County (2020)
253.7
Population per square mile in CA (2020)
2020 Population Density per Census Tract
Source: County of San Luis Obispo Public Works
CITIES & AREA Boundaries
CITy PopulationS
Source: State of California, Department of Finance, E-1 Population Estimates for Cities, Counties and the State. May 2023.
Rural or remote areas can lack easy access to public transportation, healthcare and schools, and can lead to social isolation for some. Some rural areas also have characteristics that put residents at increased risk of poorer health, like higher rates of poverty and lower rates of health insurance. The county's density has important implications for Medicare and Medicaid reimbursement rates as its “semi-rural” designation may offer fewer financial incentives to attract or retain health care workers, affecting access to care for residents.
Race and Ethnicity
The majority of residents in SLO County identify as white, followed by Hispanic or Latino.
Percent of population By Race and Ethnicity
AGE
Overall, SLO County's population is older than the population of the state as a whole. An understanding of the age of residents in our community helps project potential needs for education, child care, health care, and other services.
Births (Rate per 1,000 women)
Births in SLO County have held relatively stable in recent years, though California's birthrates have decreased.
Percent of the population age 65 and older
SLO County also has a larger percentage of those 65 years of age and older. See key demographics of the state's older adults in California's Master Plan for Aging.
Source: State of California, Department of Finance, P-3 Population Estimates for Cities, Counties and the State. May 2023.
Percent of the population under Age 18
SLO County has a smaller percentage of those 18 years of age and younger, and that percent has been declining over the last several decades.
Source: State of California, Department of Finance, P-3 Population Estimates for Cities, Counties and the State. May 2023.
Age distribution compared to California
The age distribution of SLO County diverges from the state's in several ways—namely that SLO County has fewer youths under 19 years, more adults between the ages of 20 and 29, fewer adults between the ages of 30 and 59, and more adults 60 years and older.
Source: Department of Finance Population Projections 2023. Accessed October 2023.
Demographics over Time
Since 1970, the population of the county has more than doubled, increasing from approximately 105,000 residents to just over 280,000 residents in 2024. Over this time, the demographic make-up of the county has experienced multiple changes as the population grew. Youths and adults under the age of 45 were the largest age groups in the county through the 1990s, but older age groups have been steadily growing and are expected to remain the largest age group in the coming decade. The largest racial and ethnic group in the county has been non-Hispanic White, but other racial groups have been steadily growing.
San Luis Obispo County Population Demographics 1970-2030
Source: California Department of Finance Estimates (accessed March 2024) and Projections (accessed March 2024, P-3 file from 2021 was used to obtain population estimates for 2011-2019)
Education
Education is associated with a range of positive life outcomes, from better employment and income prospects to better health and life expectancy. SLO County consistently has higher high school graduation rates compared to the state average.
91.9%
People with a high school diploma or higher in SLO County
84.2%
People with a high school diploma or higher in CA
High School Graduate or Higher, % of persons age 25 years +
Schools in slo county
K-12 education is provided by a number of public, private and charter schools throughout the county. The county also has a community college and university that support higher education and draw students from across the nation.
Languages spoken
Most residents in SLO County speak English as their primary language, followed by Spanish as the second most common language. Having limited English proficiency in the U.S. can be a barrier to accessing health care services and understanding health information; it can lead to poorer health outcomes compared with patients who speak English.
LanguageS spoken at home in SLO County (%)
Language spoken at home: spanish
Spanish is the second most common language in SLO County, with some cities having more Spanish Speakers than others.
Additionally, a growing number of people in SLO County speak Mixteco, an indigenous, non-written language spoken in Mexico. There are 81 different variants of Mixteco, most of which are so different that communicating with those who speak a different variant or with a Mixteco translator from a different region is difficult if not impossible.
"Our Mixteco clients have told us that they've been offered interpretation services, but it's in the wrong dialect and they can't understand what they're saying, or it's low quality with untrained interpreters and background noise. All of this can add up to a poor experience, making them less likely to access services the next time they need them."
- Community partner