County · code 06073
San Diego CountyCalifornia
San Diego County is a county in California with its seat in San Diego. It was created in 1850 and is named after San Diego.
- Founded1850
- County seatSan Diego
- Named forSan Diego, California
- Land area4,210 sq mi + 316 sq mi water
- Population3,298,634 2020 Census
- Parcels mapped1,089,056 checked 16 October 2026
Where it is
San Diego on the map of California
California has 58 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Founded in 1850
An old deed may name a county that no longer exists, or a boundary that has since moved.
San Diego County was created in 1850 from non-county area. In 1851 it exchanged territory with Los Angeles and Mariposa Counties. The county lost land to the creation of Riverside County in 1893 and Imperial County in 1907.
- 1850San Diego County created San Diego created from non-county area. · Calif. Stats. 1849, 1st sess., ch. 15, sec. 2/pp. 58-59
- 1851Exchanged territory San Diego exchanged with Los Angeles, lost to Mariposa. · Calif. Stats. 1851, 2d sess., ch. 14, sec. 2/p. 172
- 1868Boundary clarified San Diego boundaries clarified (no change).no change· Calif. Stats. 1867, 17th sess., ch. 453/p. 604
- 1873Gained territory San Diego gained from Los Angeles, lost to San Bernardino. · Political Code 1872, 1: secs. 3943-3945/pp. 140-142
- 1893Lost territory San Diego lost to creation of Riverside. Act passed 11 March 1893; referendum for or against creation of new county held 2 May 1893. · Calif. Stats. 1893, 30th sess., ch. 142/pp. 158-168
- 1907
Land and parcels
What the maps cover in San Diego
Who publishes each layer, how good it is, and when we last checked.
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Parcels Good enough
Lot lines and tax-map numbers for 1,089,056 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 6 October 2026 · checked 16 October 2026 -
Address points Missing
No public address points layer found for San Diego County yet.
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Buildings Reference
Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026
- Official
- from the office that keeps the record
- Good enough
- a reliable statewide or national copy
- Fallback
- a guide only; check the official record
- Missing
- nothing public found yet
People and land
San Diego by the Census
Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.
Rules and offices
San Diego County's official site
We have found the county's site but not its offices yet; start there.
County government
- County government
The official website of San Diego County.
See your own lot on these maps
Open San Diego County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.
Questions
Common questions about San Diego County
- When was San Diego County founded?
- San Diego County was founded in 1850, and named after San Diego, California.
- What is the county seat of San Diego County?
- The county seat of San Diego County is San Diego.
- Is there an online parcel map for San Diego County?
- Yes. A public source publishes a parcel map of 1,089,056 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has San Diego County's boundary or name changed?
- San Diego County was created in 1850. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Los Angeles County, Imperial County and Mariposa County.
- Is my lot in a flood zone?
- We do not have flood maps for San Diego County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby