When was Franklin County founded?

Franklin County was founded in 1803, formed from Ross County and Wayne County, and named after Benjamin Franklin.

What is the county seat of Franklin County?

The county seat of Franklin County is Columbus.

Is there an online parcel map for Franklin County?

Yes. A public source publishes a parcel map of 494,848 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Franklin County's boundary or name changed?

Franklin County was created in 1803 from Ross County and Wayne County. Since then the Atlas of Historical County Boundaries records 10 later changes, chiefly involving Madison County, Delaware County and Fairfield County.

Who issues building permits in Franklin County?

The county's page on building permits: Building Permits - Franklin County, Ohio. Inside a city or town, ask that city first.

Who issues septic and well permits in Franklin County?

The county's page on septic systems and wells: 23 Oct 2026 Veterans Stand Down October 23, 2026 The Central Ohio Veterans Stand Down event helps connect veterans in Central Ohio with resources including food, shelter, clothing, and health screenin.

Is my lot in a flood zone?

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

County · code 39049

Franklin CountyOhio

Franklin County is a county in Ohio with its county seat in Columbus. It was created on April 30, 1803, from Ross County and Non-County Area 1, and is named after Benjamin Franklin.

Founded1803
County seatColumbus
Named forBenjamin Franklin
Land area532 sq mi + 11 sq mi water
Population1,323,807 2020 Census
Parcels mapped494,848 checked 13 October 2026

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

Updated 19 October 2026

Census outline · seat marked

History

Formed in 1803 from Ross County and Wayne County

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

Franklin County was created from Ross County and Non-County Area 1 in 1803, though it briefly overlapped a small area of Wayne (Indiana Territory, extinct). Over the next two decades, the county lost territory to the creation of Champaign, Knox, Richland, Delaware, Madison, Pickaway, and Union, while gaining small areas from Fairfield and Licking.

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

1803
Franklin County created Franklin created from Ross and Non-County Area 1. Franklin overlapped a small area of Wayne (Indiana Territory, extinct).
from Ross from Wayne
30 April 1803 · Ohio Laws 1803, 1st assy., ch. 11/p. 26; Chase, 3:ch. 348/p. 2101
1805
Lost territory Franklin lost to creation of Champaign.
to Champaign
1 March 1805 · Ohio Laws 1804, 3d assy., ch. 69/p. 285; Chase, 3:ch. 342 [sic]/p. 2103
1808
Gained territory Franklin gained from Fairfield, lost to creation of Knox and Richland.
from Fairfield from Knox from Richland
1 March 1808 · Ohio Laws 1807, 6th assy., ch. 8, secs. 1-2, 7/pp. 21-24; Chase, 3:ch. 364, secs. 1-2, 7/pp. 2106-2107
1810
Lost territory Franklin lost to creation of Madison and Pickaway.
to Madison to Pickaway
1 March 1810 · Ohio Laws 1809, 8th assy., ch. 13/p. 41 and ch. 67/p. 248; Chase, 3:ch. 379/p. 2111 and ch. 385/p. 2114
1820
Lost territory Franklin lost to creation of Union and lost to Madison.
to Union to Madison
1 April 1820 · Ohio Laws 1819, 18th assy., loc., ch. 16, secs. 1, 8-9/pp. 56, 58; Chase, 3:ch. 428/p. 2133

Show all 11 changes (6 more)

1803
Franklin County created Franklin created from Ross and Non-County Area 1. Franklin overlapped a small area of Wayne (Indiana Territory, extinct).
from Ross from Wayne
30 April 1803 · Ohio Laws 1803, 1st assy., ch. 11/p. 26; Chase, 3:ch. 348/p. 2101
1805
Lost territory Franklin lost to creation of Champaign.
to Champaign
1 March 1805 · Ohio Laws 1804, 3d assy., ch. 69/p. 285; Chase, 3:ch. 342 [sic]/p. 2103
1808
Gained territory Franklin gained from Fairfield, lost to creation of Knox and Richland.
from Fairfield from Knox from Richland
1 March 1808 · Ohio Laws 1807, 6th assy., ch. 8, secs. 1-2, 7/pp. 21-24; Chase, 3:ch. 364, secs. 1-2, 7/pp. 2106-2107
1808
Lost territory Franklin lost to creation of Delaware.
to Delaware
1 April 1808 · Ohio Laws 1807, 6th assy., chs. 10, 45/pp. 29, 152; Chase, 3:ch. 365/p. 2107
1809
Changed Northern part of Franklin reverted to Non-County Area 5 that was attached to Delaware for administrative and judicial purposes.
Delaware
17 February 1809 · Ohio Laws 1808, 7th assy., ch. 27/p. 156; Chase, 3:ch. 376/p. 2110
1810
Lost territory Franklin lost to creation of Madison and Pickaway.
to Madison to Pickaway
1 March 1810 · Ohio Laws 1809, 8th assy., ch. 13/p. 41 and ch. 67/p. 248; Chase, 3:ch. 379/p. 2111 and ch. 385/p. 2114
1817
Gained territory Franklin gained small area from Licking.
from Licking
27 January 1817 · Ohio Laws 1816, 15th assy., ch. 53/p. 169; Chase, 3:ch. 410/p. 2123
1820
Lost territory Franklin lost to creation of Union and lost to Madison.
to Union to Madison
1 April 1820 · Ohio Laws 1819, 18th assy., loc., ch. 16, secs. 1, 8-9/pp. 56, 58; Chase, 3:ch. 428/p. 2133
1845
Exchanged territory Franklin exchanged with Madison.
with Madison
4 March 1845 · Ohio Laws 1844, 43d assy., loc., p. 196
1851
Gained territory Franklin gained from Fairfield.
from Fairfield
25 March 1851 · Ohio Laws 1850, 49th assy., loc., p. 150
1857
Changed Legislature authorized Franklin to gain from Madison dependent on local referendum.
Madison
3 April 1857 · Ohio Laws 1857, 52d assy., 2d sess., p. 260

Land and parcels

What the maps cover in Franklin

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

Parcels Good enough

Lot lines and tax-map numbers for 494,848 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 9 October 2026 · checked 13 October 2026
Address points Official

One point per address, 699,846 in all from Ohio Geographically Referenced Information Program (OGRIP), Ohio DAS/OIT (state GIS office).
edited 24 June 2025 · checked 13 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

Franklin by the Census

Population

1,323,807 2020 Census count

Housing units

580,903 2020 Census count

Land area

532 square miles

Water area

11 square miles

People per sq mi

2,486 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

Clerk of court: deeds and plats
Arabic Select this as your preferred language
from franklincountyohio.gov · checked 13 October 2026

Permits

Health department: septic and well
Alcohol, Drug, & Mental Health Board
from franklincountyohio.gov · checked 13 October 2026
Building Permits - Franklin County, Ohiofrom franklincountyohio.gov
Online Permit Centerfrom co-franklin-oh.smartgovcommunity.com

Zoning and code

Planning and zoning
Mid-Ohio Regional Planning Commission
from franklincountyohio.gov · checked 13 October 2026
Planning & Zoning - Franklin County, Ohiofrom franklincountyohio.gov
Zoningfrom franklincountyohio.gov

County government

County government
The official website of Franklin County.
franklincountyohio.gov

See your own lot on these maps

Open Franklin 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 Franklin County

When was Franklin County founded?: Franklin County was founded in 1803, formed from Ross County and Wayne County, and named after Benjamin Franklin.
What is the county seat of Franklin County?: The county seat of Franklin County is Columbus.
Is there an online parcel map for Franklin County?: Yes. A public source publishes a parcel map of 494,848 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Franklin County's boundary or name changed?: Franklin County was created in 1803 from Ross County and Wayne County. Since then the Atlas of Historical County Boundaries records 10 later changes, chiefly involving Madison County, Delaware County and Fairfield County.
Who issues building permits in Franklin County?: The county's page on building permits: Building Permits - Franklin County, Ohio. Inside a city or town, ask that city first.
Who issues septic and well permits in Franklin County?: The county's page on septic systems and wells: 23 Oct 2026 Veterans Stand Down October 23, 2026 The Central Ohio Veterans Stand Down event helps connect veterans in Central Ohio with resources including food, shelter, clothing, and health screenin.
Is my lot in a flood zone?: We do not have flood maps for Franklin 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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