When was Honolulu County founded?

Honolulu County was founded in 1907, formed from Oahu County and Hi County, and named after Honolulu.

What is the county seat of Honolulu County?

The county seat of Honolulu County is Honolulu.

Is there an online parcel map for Honolulu County?

Yes. Honolulu County publishes a parcel map of 171,972 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Honolulu County's boundary or name changed?

Honolulu County was created in 1907 from Oahu County and Hi County. The Atlas of Historical County Boundaries records no boundary change since.

Is my lot in a flood zone?

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

County · code 15003

Honolulu CountyHawaii

Honolulu County is the county seat of Honolulu, Hawaii, and was formed on April 30, 1907, as the City and County of Honolulu.

Founded1907
County seatHonolulu
Named forHonolulu
Land area601 sq mi + 1,566 sq mi water
Population1,016,508 2020 Census
Parcels mapped171,972 checked 14 October 2026

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

Updated 19 October 2026

Census outline · seat marked

Where it is

Honolulu on the map of Hawaii

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

Counties of Hawaii · Honolulu highlighted

History

Formed in 1907 from Oahu County and Hi County

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

Honolulu County was created from the entire Island of Oahu, along with all other islands in the Territory of Hawaii not included in any other county and the waters adjacent to them, when the City and County of Honolulu was incorporated. The county was named after Honolulu, its seat.

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

1907
Honolulu County created Honolulu created from all of Oahu when the "City and County of Honolulu" was incorporated from the "Island of Oahu, all other islands in the Territory of Hawaii not included in any other county and the waters adjacent thereto"; Oahu county eliminated.
from Oahufrom Hi
30 April 1907 · Hawaii Terr. Laws 1907, reg. sess., act 118, ch. 1/pp. 200-243

Land and parcels

What the maps cover in Honolulu

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

Parcels Good enough

Lot lines and tax-map numbers for 171,972 parcels from Honolulu County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 9 October 2026 · checked 14 October 2026
Address points Missing

No public address points layer found for Honolulu 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

Honolulu by the Census

Population

1,016,508 2020 Census count

Housing units

370,665 2020 Census count

Land area

601 square miles

Water area

1,566 square miles · 72% of the county, including large bodies of water

People per sq mi

1,692 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 Honolulu 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 Honolulu County

When was Honolulu County founded?: Honolulu County was founded in 1907, formed from Oahu County and Hi County, and named after Honolulu.
What is the county seat of Honolulu County?: The county seat of Honolulu County is Honolulu.
Is there an online parcel map for Honolulu County?: Yes. Honolulu County publishes a parcel map of 171,972 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Honolulu County's boundary or name changed?: Honolulu County was created in 1907 from Oahu County and Hi County. The Atlas of Historical County Boundaries records no boundary change since.
Is my lot in a flood zone?: We do not have flood maps for Honolulu County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.