San Diego County

Flag of San Diego County.

Seal of San Diego County.

San Diego County is a large county in the southwest area of California. The county borders Mexico. The population of San Diego County was 3,298,634 in 2020, which makes San Diego County the second most populated county in California.

San Diego County has about 70 miles (110 km) of coastline. Most people live near the coast, for example in San Diego, California.

Also in this county there are 16 military locations of the United States Navy, U.S. Marine Corps and the U.S. Coast Guard, including Naval Base San Diego, Marine Corps Base Camp Pendleton, Marine Corps Air Station Miramar, and Naval Air Station North Island.

Communities

Top 15 Most Populated Communities in San Diego County
Rank	Name	Type	Population	Average income[1]	Violent crime rate[2]	Democrats	Republicans	Others	None
1	San Diego	City	1,296,437	$33,135	4.13	40.2%	27.0%	8.2%	27.7%
2	Chula Vista	City	236,218	$25,419	2.33	42.0%	27.7%	6.9%	26.1%
3	Oceanside	City	166,139	$27,674	4.25	31.6%	37.8%	9.2%	25.1%
4	Escondido	City	142,573	$23,194	4.26	28.3%	42.4%	9.3%	23.7%
5	Carlsbad	City	102,342	$42,712	2.46	28.0%	42.0%	8.5%	24.9%
6	El Cajon	City	98,813	$21,132	3.58	33.7%	37.4%	9.5%	23.2%
7	Vista	City	93,293	$21,478	4.84	29.9%	39.6%	9.4%	24.8%
8	San Marcos	City	80,709	$25,282	2.65	29.3%	40.6%	9.1%	24.8%
9	Encinitas	City	59,223	$47,346	2.46	35.1%	32.8%	9.0%	26.4%
10	National City	City	58,015	$16,611	6.19	48.9%	19.5%	7.0%	27.2%
11	La Mesa	City	56,722	$29,958	3.83	37.9%	32.5%	9.8%	23.6%
12	Santee	City	53,302	$28,242	2.82	27.0%	43.9%	9.7%	23.2%
13	Poway	City	47,762	$41,445	1.92	24.8%	45.7%	7.8%	24.8%
14	La Presa	CDP	34,607	$22,781	N/A	N/A	N/A	N/A	N/A
15	Fallbrook	CDP	30,949	$27,512	N/A	N/A	N/A	N/A	N/A

1.^ Per capita income (meaning the added up income of all residents divided by the population.)

1.^ Per 1,000 people (as of 2012)