When was Gallia County founded?

Gallia County was founded in 1803, formed from Washington County, and named after Gaul.

What is the county seat of Gallia County?

The county seat of Gallia County is Gallipolis.

Is there an online parcel map for Gallia County?

Yes. Ohio Geographically Referenced Information Program (OGRIP, Ohio DAS) statewide compilation of county auditor parcels publishes a parcel map of 27,066 parcels, rated fallback here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Gallia County's boundary or name changed?

Gallia County was created in 1803 from Washington County. Since then the Atlas of Historical County Boundaries records 10 later changes, chiefly involving Lawrence County, Jackson County and Athens County.

Is my lot in a flood zone?

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

County · code 39053

Gallia CountyOhio

Gallia County is in Ohio, with its county seat in Gallipolis. It was created on April 30, 1803, from Washington County and named after Gaul.

Founded1803
County seatGallipolis
Named forGaul
Land area467 sq mi + 4.7 sq mi water
Population29,220 2020 Census
Parcels mapped27,066 checked 14 October 2026

Open the free map Click any parcel in Gallia 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 Washington County

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

Gallia County was created from Washington County on April 30, 1803, and named after Gaul. Over the next five decades, the county lost territory to the creation of several new counties: Scioto in 1804, Lawrence in 1815, Jackson in 1816, Meigs in 1819, and Vinton in 1850, while also exchanging small areas with Athens and Lawrence.

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

1803
Gallia County created Gallia created from Washington.
from Washington
30 April 1803 · Ohio Laws 1803, 1st assy., ch. 8/p. 19; Chase, 3:ch. 347/pp. 2100-2101
1804
Lost territory Gallia lost to Scioto.
to Scioto
29 December 1804 · Ohio Laws 1804, 3d assy., ch. 74/p. 294; Chase, 3:ch. 354/p. 2103
1815
Lost territory Gallia lost to creation of Lawrence; Lawrence not fully organized, part attached to Gallia for administrative and judicial purposes.
to Lawrence
21 December 1815 · Ohio Laws 1815, 14th assy., ch. 8/p. 22; Chase, 3:ch. 403/p. 2121
1816
Lost territory Gallia lost to creation of Jackson.
to Jackson
1 March 1816 · Ohio Laws 1815, 14th assy., ch. 25, secs. 1, 5/pp. 112, 115; Chase, 3:ch. 404/pp. 2121-2122
1818
Lost territory Gallia lost to Lawrence.
to Lawrence
22 December 1818 · Ohio Laws 1818, 17th assy., ch. 2/p. 3; Chase, 3:ch. 420/p. 2129

Show all 11 changes (6 more)

1803
Gallia County created Gallia created from Washington.
from Washington
30 April 1803 · Ohio Laws 1803, 1st assy., ch. 8/p. 19; Chase, 3:ch. 347/pp. 2100-2101
1804
Lost territory Gallia lost to Scioto.
to Scioto
29 December 1804 · Ohio Laws 1804, 3d assy., ch. 74/p. 294; Chase, 3:ch. 354/p. 2103
1807
Exchanged territory Gallia exchanged small areas with Athens.
with Athens
30 January 1807 · Ohio Laws 1806, 5th assy., ch. 39/p. 105; Chase, 3:ch. 359/p. 2105
1815
Lost territory Gallia lost to creation of Lawrence; Lawrence not fully organized, part attached to Gallia for administrative and judicial purposes.
to Lawrence
21 December 1815 · Ohio Laws 1815, 14th assy., ch. 8/p. 22; Chase, 3:ch. 403/p. 2121
1816
Lost territory Gallia lost to creation of Jackson.
to Jackson
1 March 1816 · Ohio Laws 1815, 14th assy., ch. 25, secs. 1, 5/pp. 112, 115; Chase, 3:ch. 404/pp. 2121-2122
1817
Changed Lawrence fully organized, detached from Gallia.
Lawrence
1 March 1817 · Ohio Laws 1816, 15th assy., ch. 6/p. 6; Chase, 3:ch. 407/p. 2123
1818
Lost territory Gallia lost to Lawrence.
to Lawrence
22 December 1818 · Ohio Laws 1818, 17th assy., ch. 2/p. 3; Chase, 3:ch. 420/p. 2129
1819
Lost territory Gallia lost to creation of Meigs.
to Meigs
1 April 1819 · Ohio Laws 1818, 17th assy., ch. 25, secs. 1, 6/pp. 40, 43; Chase, 3:ch. 423/pp. 2131-2132
1839
Gained territory Gallia gained small area from Lawrence.
from Lawrence
1 April 1839 · Ohio Laws 1838, 37th assy., loc., p. 229
1840
Exchanged territory Gallia exchanged small areas with Lawrence.
with Lawrence
11 February 1840 · Ohio Laws 1839, 38th assy., loc., p. 46
1850
Lost territory Gallia lost to creation of Vinton and lost to Jackson.
to Vinton to Jackson
1 April 1850 · Ohio Laws 1849, 48th assy., loc., secs. 1-3, 6/pp. 684-685

Land and parcels

What the maps cover in Gallia

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

Parcels Fallback

Lot lines and tax-map numbers for 27,066 parcels from Ohio Geographically Referenced Information Program (OGRIP, Ohio DAS) statewide compilation of county auditor parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey. This copy is a fallback, not the county's own: use it as a guide and check the official record.
edited 23 September 2026 · checked 14 October 2026
Address points Official

One point per address, 16,259 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

Gallia by the Census

Population

29,220 2020 Census count

Housing units

13,430 2020 Census count

Land area

467 square miles

Water area

4.7 square miles

People per sq mi

63 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

Gallia 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 Gallia County.
gallianet.net

See your own lot on these maps

Open Gallia 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 Gallia County

When was Gallia County founded?: Gallia County was founded in 1803, formed from Washington County, and named after Gaul.
What is the county seat of Gallia County?: The county seat of Gallia County is Gallipolis.
Is there an online parcel map for Gallia County?: Yes. Ohio Geographically Referenced Information Program (OGRIP, Ohio DAS) statewide compilation of county auditor parcels publishes a parcel map of 27,066 parcels, rated fallback here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Gallia County's boundary or name changed?: Gallia County was created in 1803 from Washington County. Since then the Atlas of Historical County Boundaries records 10 later changes, chiefly involving Lawrence County, Jackson County and Athens County.
Is my lot in a flood zone?: We do not have flood maps for Gallia County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby