When was Washington County founded?

Washington County was founded in 1729, formed from Providence County, and named after George Washington.

What is the county seat of Washington County?

The county seat of Washington County is South Kingstown.

Is there an online parcel map for Washington County?

Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.

Has Washington County's boundary or name changed?

Washington County was created in 1729 from Providence County. Since then the Atlas of Historical County Boundaries records 2 later changes, chiefly involving Kings County and Newport County. It was formerly called Kings.

Is my lot in a flood zone?

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

County · code 44009

Washington CountyRhode Island

Washington County is a county in Rhode Island with its seat in South Kingstown. The county was formed in 1729 from Providence.

Founded1729
County seatSouth Kingstown
Named forGeorge Washington
Land area329 sq mi + 234 sq mi water
Population129,839 2020 Census

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

Updated 19 October 2026

Census outline · seat marked

Where it is

Washington on the map of Rhode Island

Rhode Island has 5 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of Rhode Island · Washington highlighted

History

Formed in 1729 from Providence County

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

Originally called Kings, it was created from Providence on June 16, 1729. Kings was renamed Washington on October 29, 1781. In 1963, Washington County gained Block Island from Newport County.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1729
Washington County created Kings (now Washington) created from Providence.
from Providence
16 June 1729 · R.I. Recs., 4:427
1781
Renamed Kings renamed Washington.
formerly Kings
29 October 1781 · R.I. Recs., 9:484
1963
Gained territory Washington gained Block Island from Newport.
from Newport
6 May 1963 · R.I. Acts and Resolves, 1963, ch. 84, sec. 1/p. 300

Land and parcels

What the maps cover in Washington

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

Parcels Missing

No public parcel map found for Washington County yet. Lot lines and owners of record are kept by the county assessor's office.
Address points Official

One point per address, 70,491 in all from RI E 9-1-1 Uniform Emergency Telephone System (maintained with AK Associates), published by RIGIS (URI Environmental Data Center, the state's GIS clearinghouse).
edited 11 September 2026 · checked 14 October 2026
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

Washington by the Census

Population

129,839 2020 Census count

Housing units

65,694 2020 Census count

Land area

329 square miles

Water area

234 square miles · 41% of the county, including large bodies of water

People per sq mi

394 population ÷ land area

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

See your own lot on these maps

Open Washington 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 Washington County

When was Washington County founded?: Washington County was founded in 1729, formed from Providence County, and named after George Washington.
What is the county seat of Washington County?: The county seat of Washington County is South Kingstown.
Is there an online parcel map for Washington County?: Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.
Has Washington County's boundary or name changed?: Washington County was created in 1729 from Providence County. Since then the Atlas of Historical County Boundaries records 2 later changes, chiefly involving Kings County and Newport County. It was formerly called Kings.
Is my lot in a flood zone?: We do not have flood maps for Washington County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

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