Arroyo Grande (Spanish for "Big Creek") is a city in San Luis Obispo County, California, United States. The population was 18,441 as of the 2020 census, up from 17,252 as of the 2010 census.

In 1862, the San Luis Obispo Board of Supervisors established the township of Arroyo Grande. Businesses developed along a road called Branch Street to serve local agriculture. A railroad depot was built in 1882. The city of Arroyo Grande was incorporated on July 10, 1911.

Arroyo Grande experienced rapid growth in the 1970s and 1980s, partially due to the expansion of the wastewater treatment plant, under an EPA Clean Water Grant, that removed a growth constraint. This federal grant program required preparation of an Environmental Impact Report, which provided much of the initial environmental database for Arroyo Grande.

Arroyo Grande is a small coastal town with historic, suburban, and rural elements located at 35°7′15″N 120°35′12″W / 35.12083°N 120.58667°W / 35.12083; -120.58667 (35.120878, -120.586799).

Arroyo Grande is located in a coastal ecosystem within the California Floristic Province, and the native habitats include coast live oak woodland, central coastal scrub, willow and mixed riparian along Arroyo Grande Creek and numerous tributaries, native bunch-grass grassland, coastal prairie, dunes and intertidal zone, and non-native and agricultural areas.

According to the United States Census Bureau, the city has a total area of 5.8 square miles (15 km), all of it land.

Arroyo Grande has a Temperate-Mediterranean climate (Köppen climate classification Csb).

Historical population

Census	Pop.	Note	%±
1890	466		—
1920	760		—
1930	892		17.4%
1940	1,090		22.2%
1950	1,723		58.1%
1960	3,291		91.0%
1970	7,454		126.5%
1980	11,290		51.5%
1990	14,378		27.4%
2000	15,851		10.2%
2010	17,252		8.8%
2020	18,441		6.9%
U.S. Decennial Census

At the 2010 census, Arroyo Grande had a population of 17,252. The population density was 2,956.5 inhabitants per square mile (1,141.5/km). The racial makeup of Arroyo Grande was 14,710 (85.3%) White, 156 (0.9%) African American, 125 (0.7%) Native American, 595 (3.4%) Asian, 14 (0.1%) Pacific Islander, 856 (5.0%) from other races, and 796 (4.6%) from two or more races. Hispanic or Latino of any race were 2,707 persons (15.7%).

The census reported that 17,078 people (99.0% of the population) lived in households, 62 (0.4%) lived in non-institutionalized group quarters, and 112 (0.6%) were institutionalized.

There were 7,087 households, 2,027 (28.6%) had children under the age of 18 living in them, 3,741 (52.8%) were opposite-sex married couples living together, 653 (9.2%) had a female householder with no husband present, 275 (3.9%) had a male householder with no wife present. There were 346 (4.9%) unmarried opposite-sex partnerships, and 42 (0.6%) same-sex married couples or partnerships. 1,968 households (27.8%) were one person and 1,017 (14.4%) had someone living alone who was 65 or older. The average household size was 2.41. There were 4,669 families (65.9% of households); the average family size was 2.93.

The age distribution was 3,633 people (21.1%) under the age of 18, 1,193 people (6.9%) aged 18 to 24, 3,704 people (21.5%) aged 25 to 44, 5,229 people (30.3%) aged 45 to 64, and 3,493 people (20.2%) who were 65 or older. The median age was 45.4 years. For every 100 females, there were 92.6 males. For every 100 females age 18 and over, there were 88.4 males.

There were 7,628 housing units at an average density of 1,307.2 per square mile, of the occupied units 4,686 (66.1%) were owner-occupied and 2,401 (33.9%) were rented. The homeowner vacancy rate was 1.9%; the rental vacancy rate was 4.0%. 11,345 people (65.8% of the population) lived in owner-occupied housing units and 5,733 people (33.2%) lived in rental housing units.

At the 2000 census, there were 15,851 people in 6,478 households, including 4,353 families, in the city. The population density was 2,795.3 inhabitants per square mile (1,079.3/km). There were 6,750 housing units at an average density of 1,190.3 per square mile (459.6/km). The racial makeup of the city was 88.45% White, 0.62% African American, 0.45% Native American, 3.08% Asian, 0.18% Pacific Islander, 3.77% from other races, and 3.45% from two or more races. Hispanic or Latino of any race were 11.17% of the population.

Of the 6,478 households 29.0% had children under the age of 18 living with them, 55.0% were married couples living together, 9.4% had a female householder with no husband present, and 32.8% were non-families. 27.3% of households were one person and 14.4% were one person aged 65 or older. The average household size was 2.41 and the average family size was 2.94.

The age distribution was 23.3% under the age of 18, 6.7% from 18 to 24, 25.1% from 25 to 44, 24.6% from 45 to 64, and 20.3% 65 or older. The median age was 42 years. For every 100 females, there were 88.9 males. For every 100 females age 18 and over, there were 84.5 males.

The median income for a household in the city was $48,236, and the median family income was $55,494. Males had a median income of $41,304 versus $30,688 for females. The per capita income for the city was $24,311. About 4.3% of families and 6.9% of the population were below the poverty line, including 6.8% of those under age 18 and 5.4% of those age 65 or over.

In the California State Legislature, Arroyo Grande is in the 17th Senate District, represented by Democrat John Laird, and in the 30th Assembly District, represented by Democrat Dawn Addis.

In the United States House of Representatives, Arroyo Grande is in California's 24th congressional district, represented by Democrat Salud Carbajal.

• Sally Jane Bruce - actress in The Night of the Hunter
• Zac Efron - actor
• Lou Ferrigno - TV and movie actor, best known for the title role in The Incredible Hulk
• Paul Flores - murderer of Kristin Smart
• Horace Grant - former professional basketball player
• Jordan Hasay - middle-distance runner
• Robert Hunter - lyricist and singer-songwriter
• Gladys Ingle - early 20th-century woman pilot, wing walker, and aerial stunt performer
• Ken Napzok - broadcaster, comedian, author of Why We Love Star Wars: The Great Moments That Built a Galaxy Far, Far Away
• Rita Quigley - film actress
• Harry Shum Jr. - actor, dancer and choreographer
• Sheila Varian - breeder of Arabian horses
• Robin Ventura - former professional baseball player and manager of Chicago White Sox
• Jimy Williams - former baseball manager

• Lopez Lake
• Arroyo Grande High School
• Cypress Ridge Golf Course

• Official website
• Arroyo Grande & Grover Beach Chamber Of Commerce