When was Solano County founded?

Solano County was founded in 1850, and named after Chief Solano.

What is the county seat of Solano County?

The county seat of Solano County is Fairfield.

Is there an online parcel map for Solano County?

Yes. Solano County publishes a parcel map of 153,430 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Solano County's boundary or name changed?

Solano County was created in 1850. Since then the Atlas of Historical County Boundaries records 7 later changes, chiefly involving Yolo County, Sonoma County and Napa County.

Is my lot in a flood zone?

We do not have flood maps for Solano County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 06095

Solano CountyCalifornia

Solano County is a county in California with its seat in Fairfield, formed on February 18, 1850. The county is named after Chief Solano.

Founded1850
County seatFairfield
Named forChief Solano
Land area822 sq mi + 84 sq mi water
Population453,491 2020 Census
Parcels mapped153,430 checked 16 October 2026

Open the free map Click any parcel in Solano County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 19 October 2026

Census outline · seat marked

History

Founded in 1850

An old deed may name a county that no longer exists, or a boundary that has since moved.

Solano County was created on February 18, 1850 from non-county area. In 1853, Solano County gained Mare Island, a non-county area that had previously been part of Sonoma County, and in 1855 gained additional territory from Sonoma County. Over time, Solano County lost territory to neighboring counties: to Napa County in 1855, to Yolo County in 1857 and again in 1980 and 1992, and to Sacramento County in 1870.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

1850
Solano County created Solano created from non-county area. 18 February 1850 · Calif. Stats. 1849, 1st sess., ch. 15, sec. 13/p. 61
1853
Gained territory Solano gained Mare Island, a non-county area that had been part of Sonoma until 3 May 1852.
from Sonoma
27 January 1853 · Calif. Stats. 1853, 4th sess., ch. 5/p. 20
1855
Lost territory Solano lost to Napa.
to Napa
4 April 1855 · Calif. Stats. 1855, 6th sess., ch. 68/p. 77
1855
Gained territory Solano gained from Sonoma.
from Sonoma
27 April 1855 · Calif. Stats. 1855, 6th sess., ch. 125/p. 150
1857
Lost territory Solano lost to Yolo.
to Yolo
26 March 1857 · Calif. Stats. 1857, 8th sess., ch. 104/p. 108

Show all 9 changes (4 more, mostly small adjustments)

1850
Solano County created Solano created from non-county area. 18 February 1850 · Calif. Stats. 1849, 1st sess., ch. 15, sec. 13/p. 61
1851
Boundary clarified Solano boundaries redefined (no change).
no change
25 April 1851 · Calif. Stats. 1851, 2d sess., ch. 14, sec. 27/p. 179
1853
Gained territory Solano gained Mare Island, a non-county area that had been part of Sonoma until 3 May 1852.
from Sonoma
27 January 1853 · Calif. Stats. 1853, 4th sess., ch. 5/p. 20
1855
Lost territory Solano lost to Napa.
to Napa
4 April 1855 · Calif. Stats. 1855, 6th sess., ch. 68/p. 77
1855
Gained territory Solano gained from Sonoma.
from Sonoma
27 April 1855 · Calif. Stats. 1855, 6th sess., ch. 125/p. 150
1857
Lost territory Solano lost to Yolo.
to Yolo
26 March 1857 · Calif. Stats. 1857, 8th sess., ch. 104/p. 108
1870
Lost territory Solano lost small area to Sacramento.
to Sacramento
12 March 1870 · Calif. Stats. 1869, 18th sess., ch. 191/p. 294
1980
Lost territory Solano lost small area to Yolo. Ordinance passed 20 November 1979; effective 1 January 1980.
to Yolo
1 January 1980 · Minutes of the Board of Supervisors, Solano County, 20 November 1979, ordinance 1085; Minutes of the Board of Supervisors, Yolo County, 20 November 1979, ordinance 861
1992
Lost territory Solano lost small area to Yolo.
to Yolo
18 December 1992 · Minutes of the Board of Supervisors, Solano County, 8 December 1992, ordinance 1460; Minutes of the Board of Supervisors, Yolo County, 24 November 1992, ordinance 1153

Land and parcels

What the maps cover in Solano

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 153,430 parcels from Solano County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 5 October 2026 · checked 16 October 2026
Address points Missing

No public address points layer found for Solano County yet.
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

Solano by the Census

Population

453,491 2020 Census count

Housing units

162,237 2020 Census count

Land area

822 square miles

Water area

84 square miles

People per sq mi

552 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Who to ask before you build, dig or sell

Official county pages only. We link to them; we do not copy them, because they change.

Inside a city or town, permits usually come from that city rather than the county.

Records

Assessor and property recordsfrom solanocounty.gov · checked 13 October 2026
Clerk of court: deeds and platsfrom solanocounty.gov · checked 13 October 2026

Zoning and code

Planning and zoningfrom solanocounty.gov · checked 13 October 2026
Zoning Administrator - Cancelledfrom solanocounty.gov
Solano County Zoning Administratorfrom solanocounty.gov

County government

County government
The official website of Solano County.
solanocounty.gov

See your own lot on these maps

Open Solano 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.

Open the free map no sign-in Pro early access

Questions

Common questions about Solano County

When was Solano County founded?: Solano County was founded in 1850, and named after Chief Solano.
What is the county seat of Solano County?: The county seat of Solano County is Fairfield.
Is there an online parcel map for Solano County?: Yes. Solano County publishes a parcel map of 153,430 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Solano County's boundary or name changed?: Solano County was created in 1850. Since then the Atlas of Historical County Boundaries records 7 later changes, chiefly involving Yolo County, Sonoma County and Napa County.
Is my lot in a flood zone?: We do not have flood maps for Solano County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby