County
| FIPS Code [2] | County Seat [3] | Created [3][4] | Origin [5] | Etymology [4][5] | Population [2][3] | Area [3] | Map |
| Adams County | 001 | West Union | July 10, 1797 | Hamilton County | John Adams (1735-1826), President when the county was organized | &0000000000027330.00000027,330 | &0000000000000583.910000583.91 sq mi (&0000000000001512.0000001,512 km²) |  |
| Allen County | 003 | Lima | March 1, 1820 | Shelby County | John Allen (1771/2-1813), a War of 1812 officer[6] | &0000000000108473.000000108,473 | &0000000000000404.430000404.43 sq mi (&0000000000001047.0000001,047 km²) |  |
| Ashland County | 005 | Ashland | February 24, 1846 | Wayne, Richland, Huron, and Lorain Counties | Ashland, home of Henry Clay and county seat. | &0000000000052523.00000052,523 | &0000000000000424.370000424.37 sq mi (&0000000000001099.0000001,099 km²) |  |
| Ashtabula County | 007 | Jefferson | June 7, 1807 | Trumbull and Geauga Counties | Ashtabula River, which means "fish river" in an Algonquian language[7] | &0000000000102728.000000102,728 | &0000000000000702.440000702.44 sq mi (&0000000000001819.0000001,819 km²) |  |
| Athens County | 009 | Athens | March 1, 1805 | Washington County | Athens, Greece | &0000000000062223.00000062,223 | &0000000000000506.760000506.76 sq mi (&0000000000001313.0000001,313 km²) |  |
| Auglaize County | 011 | Wapakoneta | February 14, 1848 | Allen, Mercer, Darke, Hardin, Logan, Shelby, and Van Wert Counties | Auglaize River, which means "fallen timbers river" to the Shawnee | &0000000000046611.00000046,611 | &0000000000000401.250000401.25 sq mi (&0000000000001039.0000001,039 km²) |  |
| Belmont County | 013 | St. Clairsville | September 7, 1801 | Jefferson and Washington Counties | Belle monte, which means "beautiful mountain" in French | &0000000000070226.00000070,226 | &0000000000000537.350000537.35 sq mi (&0000000000001392.0000001,392 km²) |  |
| Brown County | 015 | Georgetown | March 1, 1818 | Adams and Clermont Counties | General Jacob Brown (1775-1828), an officer of the War of 1812 | &0000000000042285.00000042,285 | &0000000000000491.760000491.76 sq mi (&0000000000001274.0000001,274 km²) |  |
| Butler County | 017 | Hamilton | May 1, 1803 | Hamilton County | General Richard Butler (1743-1791), killed at the Battle of the Wabash | &0000000000332807.000000332,807 | &0000000000000467.270000467.27 sq mi (&0000000000001210.0000001,210 km²) |  |
| Carroll County | 019 | Carrollton | January 1, 1833 | Columbiana, Stark, Harrison, Jefferson, and Tuscarawas Counties | Charles Carroll (1737-1832), last surviving signer of the United States Declaration of Independence | &0000000000028836.00000028,836 | &0000000000000394.670000394.67 sq mi (&0000000000001022.0000001,022 km²) |  |
| Champaign County | 021 | Urbana | March 1, 1805 | Greene and Franklin Counties | French for "a plain", describing the land in the area | &0000000000038890.00000038,890 | &0000000000000428.560000428.56 sq mi (&0000000000001110.0000001,110 km²) |  |
| Clark County | 023 | Springfield | March 1, 1818 | Champaign, Madison, and Greene Counties | General George Rogers Clark (1752-1818), defeated the Shawnee Indians in a battle near the Springfield area | &0000000000144742.000000144,742 | &0000000000000399.860000399.86 sq mi (&0000000000001036.0000001,036 km²) |  |
| Clermont County | 025 | Batavia | December 6, 1800 | Hamilton County | French for "clear mountain" | &0000000000177977.000000177,977 | &0000000000000451.990000451.99 sq mi (&0000000000001171.0000001,171 km²) |  |
| Clinton County | 027 | Wilmington | March 1, 1810 | Highland and Warren Counties | George Clinton (1739-1812), vice-president when the county was organized | &0000000000040543.00000040,543 | &0000000000000410.880000410.88 sq mi (&0000000000001064.0000001,064 km²) |  |
| Columbiana County | 029 | Lisbon | May 1, 1803 | Jefferson and Washington Counties | Derived from the words Christopher Columbus and Anna | &0000000000112075.000000112,075 | &0000000000000532.460000532.46 sq mi (&0000000000001379.0000001,379 km²) |  |
| Coshocton County | 031 | Coshocton | January 31, 1810 | Muskingum and Tuscarawas Counties | Delaware Indian word meaning "union of waters" | &0000000000036655.00000036,655 | &0000000000000564.070000564.07 sq mi (&0000000000001461.0000001,461 km²) |  |
| Crawford County | 033 | Bucyrus | April 1, 1820 | Delaware County | Colonel William Crawford (1732-1782), Revolutionary War officer | &0000000000046966.00000046,966 | &0000000000000402.110000402.11 sq mi (&0000000000001041.0000001,041 km²) |  |
| Cuyahoga County | 035 | Cleveland | June 7, 1807 | Geauga County | Cuyahoga River, which means "crooked river" in an Iroquoian language[8] | &0000000001393978.0000001,393,978 | &0000000000000458.490000458.49 sq mi (&0000000000001187.0000001,187 km²) |  |
| Darke County | 037 | Greenville | January 3, 1809 | Miami County | General William Darke (1736-1801), Revolutionary War officer | &0000000000053309.00000053,309 | &0000000000000599.800000599.80 sq mi (&0000000000001553.0000001,553 km²) |  |
| Defiance County | 039 | Defiance | April 7, 1845 | Williams, Henry, and Paulding Counties | Fort Defiance, built in 1794 by General Anthony Wayne | &0000000000039500.00000039,500 | &0000000000000411.160000411.16 sq mi (&0000000000001065.0000001,065 km²) |  |
| Delaware County | 041 | Delaware | April 1, 1808 | Franklin County | Delaware Indians | &0000000000110106.000000110,106 | &0000000000000442.410000442.41 sq mi (&0000000000001146.0000001,146 km²) |  |
| Erie County | 043 | Sandusky | March 15, 1838 | Huron and Sandusky Counties | Erie Indians | &0000000000079551.00000079,551 | &0000000000000254.880000254.88 sq mi (&0000000000000660.000000660 km²) |  |
| Fairfield County | 045 | Lancaster | December 9, 1800 | Ross and Washington Counties | Named for the beauty of its "fair fields" | &0000000000122759.000000122,759 | &0000000000000505.110000505.11 sq mi (&0000000000001308.0000001,308 km²) |  |
| Fayette County | 047 | Washington Court House | March 1, 1810 | Ross and Highland Counties | Marquis de Lafayette, French military officer and aristocrat who participated in both the American and French revolutions. | &0000000000028433.00000028,433 | &0000000000000406.580000406.58 sq mi (&0000000000001053.0000001,053 km²) |  |
| Franklin County | 049 | Columbus | April 30, 1803 | Ross and Wayne Counties | Benjamin Franklin (1706-1791) - Founding Father, author, printer, satirist, political theorist, scientist, inventor and statesman. | &0000000001068978.0000001,068,978 | &0000000000000539.870000539.87 sq mi (&0000000000001398.0000001,398 km²) |  |
| Fulton County | 051 | Wauseon | April 1, 1850 | Lucas, Henry, and Williams Counties | Robert Fulton (1765 – 1815), inventor of the steamboat | &0000000000042084.00000042,084 | &0000000000000406.780000406.78 sq mi (&0000000000001054.0000001,054 km²) |  |
| Gallia County | 053 | Gallipolis | April 30, 1803 | Washington and Adams Counties | Gaul, the ancient name of France | &0000000000031069.00000031,069 | &0000000000000468.780000468.78 sq mi (&0000000000001214.0000001,214 km²) |  |
| Geauga County | 055 | Chardon | March 1, 1806 | Trumbull County | A Native American word meaning "raccoon" | &0000000000090895.00000090,895 | &0000000000000403.660000403.66 sq mi (&0000000000001045.0000001,045 km²) |  |
| Greene County | 057 | Xenia | May 1, 1803 | Hamilton and Ross Counties | General Nathanael Greene (1742-1786), Revolutionary War officer | &0000000000147886.000000147,886 | &0000000000000414.880000414.88 sq mi (&0000000000001075.0000001,075 km²) |  |
| Guernsey County | 059 | Cambridge | March 1, 1810 | Belmont and Muskingum Counties | Island of Guernsey, from where most of the settlers originated | &0000000000040792.00000040,792 | &0000000000000521.900000521.90 sq mi (&0000000000001352.0000001,352 km²) |  |
| Hamilton County | 061 | Cincinnati | January 2, 1790 | One of the original counties | Alexander Hamilton (1755/7-1804), Secretary of the Treasury when the county was organized | &0000000000845303.000000845,303 | &0000000000000407.360000407.36 sq mi (&0000000000001055.0000001,055 km²) |  |
| Hancock County | 063 | Findlay | April 1, 1820 | Logan County | John Hancock (1737-1793), president of the Continental Congress | &0000000000071295.00000071,295 | &0000000000000531.350000531.35 sq mi (&0000000000001376.0000001,376 km²) |  |
| Hardin County | 065 | Kenton | April 1, 1820 | Logan County | General John Hardin (1753–1792), Revolutionary War officer | &0000000000031945.00000031,945 | &0000000000000470.290000470.29 sq mi (&0000000000001218.0000001,218 km²) |  |
| Harrison County | 067 | Cadiz | February 1, 1813 | Jefferson and Tuscarawas Counties | General William Henry Harrison (1773–1841), an officer of the War of 1812 | &0000000000015856.00000015,856 | &0000000000000403.530000403.53 sq mi (&0000000000001045.0000001,045 km²) |  |
| Henry County | 069 | Napoleon | April 1, 1820 | Shelby County | Patrick Henry (1736–1799), Revolutionary War officer | &0000000000029210.00000029,210 | &0000000000000416.500000416.50 sq mi (&0000000000001079.0000001,079 km²) |  |
| Highland County | 071 | Hillsboro | May 1, 1805 | Ross, Adams, and Clermont Counties | Descriptive of the county's terrain | &0000000000040875.00000040,875 | &0000000000000553.280000553.28 sq mi (&0000000000001433.0000001,433 km²) |  |
| Hocking County | 073 | Logan | March 1, 1818 | Athens, Ross, and Fairfield Counties | Possibly derived from the Delaware Indian word "Hoch-Hoch-ing", meaning "bottle" | &0000000000028241.00000028,241 | &0000000000000422.750000422.75 sq mi (&0000000000001095.0000001,095 km²) |  |
| Holmes County | 075 | Millersburg | January 20, 1824 | Coshocton, Wayne, and Tuscarawas Counties | Major Andrew Holmes (d. 1814), a War of 1812 officer | &0000000000038943.00000038,943 | &0000000000000422.990000422.99 sq mi (&0000000000001096.0000001,096 km²) |  |
| Huron County | 077 | Norwalk | March 7, 1809 | Portage and Cuyahoga Counties | Huron Indians | &0000000000059847.00000059,847 | &0000000000000492.690000492.69 sq mi (&0000000000001276.0000001,276 km²) |  |
| Jackson County | 079 | Jackson | March 1, 1816 | Scioto, Gallia, Athens, and Ross Counties | General Andrew Jackson (1767–1845) | &0000000000032641.00000032,641 | &0000000000000420.280000420.28 sq mi (&0000000000001089.0000001,089 km²) |  |
| Jefferson County | 081 | Steubenville | July 29, 1797 | Washington County | Thomas Jefferson (1743–1826), Vice President when the county was organized | &0000000000073894.00000073,894 | &0000000000000409.610000409.61 sq mi (&0000000000001061.0000001,061 km²) |  |
| Knox County | 083 | Mount Vernon | March 1, 1808 | Fairfield County | General Henry Knox, the first Secretary of War | &0000000000054500.00000054,500 | &0000000000000527.120000527.12 sq mi (&0000000000001365.0000001,365 km²) |  |
| Lake County | 085 | Painesville | March 6, 1840 | Geauga and Cuyahoga Counties | Named as such due to it bordering Lake Erie | &0000000000227511.000000227,511 | &0000000000000228.210000228.21 sq mi (&0000000000000591.000000591 km²) |  |
| Lawrence County | 087 | Ironton | December 21, 1815 | Gallia and Scioto Counties | Captain James Lawrence (1781–1813), naval hero in the War of 1812 | &0000000000062319.00000062,319 | &0000000000000454.960000454.96 sq mi (&0000000000001178.0000001,178 km²) |  |
| Licking County | 089 | Newark | March 1, 1808 | Fairfield County | Named for the salt licks in the area | &0000000000145491.000000145,491 | &0000000000000686.500000686.50 sq mi (&0000000000001778.0000001,778 km²) |  |
| Logan County | 091 | Bellefontaine | March 1, 1818 | Champaign County | General Benjamin Logan (c.1742–1802) , who destroyed Shawnee Indian towns in the county | &0000000000046005.00000046,005 | &0000000000000458.440000458.44 sq mi (&0000000000001187.0000001,187 km²) |  |
| Lorain County | 093 | Elyria | December 26, 1822 | Huron, Cuyahoga, and Medina Counties | Province of Lorraine, France | &0000000000284664.000000284,664 | &0000000000000492.500000492.50 sq mi (&0000000000001276.0000001,276 km²) |  |
| Lucas County | 095 | Toledo | June 20, 1835 | Wood, Sandusky, and Huron Counties | Robert Lucas (1781–1853), Governor of Ohio when the county was created | &0000000000455054.000000455,054 | &0000000000000340.460000340.46 sq mi (&0000000000000882.000000882 km²) |  |
| Madison County | 097 | London | March 1, 1810 | Franklin County | President James Madison (1751-1836) | &0000000000040213.00000040,213 | &0000000000000465.440000465.44 sq mi (&0000000000001205.0000001,205 km²) |  |
| Mahoning County | 099 | Youngstown | March 1, 1846 | Columbiana and Trumbull Counties | Mahoning River, a Native American word meaning "at the licks" | &0000000000257555.000000257,555 | &0000000000000415.250000415.25 sq mi (&0000000000001075.0000001,075 km²) |  |
| Marion County | 101 | Marion | April 1, 1820 | Delaware County | General Francis Marion (1732-1795), lieutenant colonel in the Continental Army and later brigadier general in the American Revolutionary War. | &0000000000066217.00000066,217 | &0000000000000403.840000403.84 sq mi (&0000000000001046.0000001,046 km²) |  |
| Medina County | 103 | Medina | February 18, 1812 | Portage County | Medina, capital of the Al Madinah Province in western Saudi Arabia | &0000000000151095.000000151,095 | &0000000000000421.550000421.55 sq mi (&0000000000001092.0000001,092 km²) |  |
| Meigs County | 105 | Pomeroy | April 1, 1819 | Gallia and Athens Counties | Return Jonathan Meigs, Jr. (1764-1825), Governor of Ohio and Postmaster General at the time the county was organized | &0000000000023072.00000023,072 | &0000000000000429.420000429.42 sq mi (&0000000000001112.0000001,112 km²) |  |
| Mercer County | 107 | Celina | April 1, 1820 | Darke County | General Hugh Mercer (1726-1777), a Revolutionary War officer | &0000000000040924.00000040,924 | &0000000000000463.270000463.27 sq mi (&0000000000001200.0000001,200 km²) |  |
| Miami County | 109 | Troy | March 1, 1807 | Montgomery County | Miami Indians | &0000000000098868.00000098,868 | &0000000000000407.040000407.04 sq mi (&0000000000001054.0000001,054 km²) |  |
| Monroe County | 111 | Woodsfield | January 29, 1813 | Belmont, Washington, and Guernsey Counties | James Monroe (1758-1831), Secretary of State when the county was organized | &0000000000015180.00000015,180 | &0000000000000455.540000455.54 sq mi (&0000000000001180.0000001,180 km²) |  |
| Montgomery County | 113 | Dayton | May 1, 1803 | Hamilton and Wayne Counties | General Richard Montgomery (1738-1775), a Revolutionary War officer | &0000000000559062.000000559,062 | &0000000000000461.680000461.68 sq mi (&0000000000001196.0000001,196 km²) |  |
| Morgan County | 115 | McConnelsville | December 29, 1817 | Washington, Guernsey, and Muskingum Counties | General Daniel Morgan (c.1735–1802), a Revolutionary War officer | &0000000000014897.00000014,897 | &0000000000000417.660000417.66 sq mi (&0000000000001082.0000001,082 km²) |  |
| Morrow County | 117 | Mount Gilead | March 1, 1848 | Knox, Marion, Delaware, and Richland Counties | Jeremiah Morrow (1771–1852), Governor of Ohio | &0000000000031628.00000031,628 | &0000000000000406.220000406.22 sq mi (&0000000000001052.0000001,052 km²) |  |
| Muskingum County | 119 | Zanesville | March 1, 1803 | Washington and Fairfield Counties | A Native American word meaning "A town by the river" or a Native American word meaning "by the river side" | &0000000000084585.00000084,585 | &0000000000000664.630000664.63 sq mi (&0000000000001721.0000001,721 km²) |  |
| Noble County | 121 | Caldwell | April 1, 1851 | Monroe, Washington, Morgan, and Guernsey Counties | James Noble (1785–1831), an early settler | &0000000000014058.00000014,058 | &0000000000000399.000000399.00 sq mi (&0000000000001033.0000001,033 km²) |  |
| Ottawa County | 123 | Port Clinton | March 6, 1840 | Erie, Sandusky, and Lucas Counties | Named for the Ottawa Indians; Ottawa means "trader" in their language | &0000000000040985.00000040,985 | &0000000000000254.950000254.95 sq mi (&0000000000000660.000000660 km²) |  |
| Paulding County | 125 | Paulding | April 1, 1820 | Darke County | John Paulding (1758–1818), captor of spy John André during the Revolutionary War | &0000000000020293.00000020,293 | &0000000000000416.260000416.26 sq mi (&0000000000001078.0000001,078 km²) |  |
| Perry County | 127 | New Lexington | March 1, 1818 | Washington, Fairfield, and Muskingum Counties | Commodore Oliver Hazard Perry (1785–1819), a naval officer of the War of 1812 | &0000000000034078.00000034,078 | &0000000000000409.780000409.78 sq mi (&0000000000001061.0000001,061 km²) |  |
| Pickaway County | 129 | Circleville | March 1, 1810 | Ross, Fairfield, and Franklin Counties | A misspelling of the Piqua tribe, a branch of the Shawnee or A variant of a Native American word "Piqua" | &0000000000052727.00000052,727 | &0000000000000501.910000501.91 sq mi (&0000000000001300.0000001,300 km²) |  |
| Pike County | 131 | Waverly | February 1, 1815 | Ross, Scioto, and Adams Counties | General Zebulon M. Pike (1779–1813), a Revolutionary War officer and discoverer of Pikes Peak in Colorado in 1806 | &0000000000027695.00000027,695 | &0000000000000441.490000441.49 sq mi (&0000000000001143.0000001,143 km²) |  |
| Portage County | 133 | Ravenna | June 7, 1807 | Trumbull County | Derived from an Indian portage | &0000000000152061.000000152,061 | &0000000000000492.390000492.39 sq mi (&0000000000001275.0000001,275 km²) |  |
| Preble County | 135 | Eaton | March 1, 1808 | Montgomery and Butler Counties | Captain Edward Preble (1761-1807), a Naval commander in the Revolutionary War | &0000000000042337.00000042,337 | &0000000000000424.800000424.80 sq mi (&0000000000001100.0000001,100 km²) |  |
| Putnam County | 137 | Ottawa | April 1, 1820 | Shelby County | General Israel Putnam (1718–1790), a Revolutionary War officer | &0000000000034726.00000034,726 | &0000000000000483.870000483.87 sq mi (&0000000000001253.0000001,253 km²) |  |
| Richland County | 139 | Mansfield | March 1, 1808 | Fairfield County | Descriptive of the soil in the area | &0000000000128852.000000128,852 | &0000000000000496.880000496.88 sq mi (&0000000000001287.0000001,287 km²) |  |
| Ross County | 141 | Chillicothe | August 20, 1798 | Adams and Washington Counties | Named for James Ross by territorial governor Arthur St. Clair | &0000000000073345.00000073,345 | &0000000000000688.410000688.41 sq mi (&0000000000001783.0000001,783 km²) |  |
| Sandusky County | 143 | Fremont | April 1, 1820 | Huron County | An Iroquois word meaning "cold water" | &0000000000061792.00000061,792 | &0000000000000409.180000409.18 sq mi (&0000000000001060.0000001,060 km²) |  |
| Scioto County | 145 | Portsmouth | May 1, 1803 | Adams County | Scioto River; Scioto is a Wyandot word meaning "deer" | &0000000000079195.00000079,195 | &0000000000000612.270000612.27 sq mi (&0000000000001586.0000001,586 km²) |  |
| Seneca County | 147 | Tiffin | April 1, 1820 | Huron County | Seneca Indians, who had a reservation in the county area at the time | &0000000000058683.00000058,683 | &0000000000000550.590000550.59 sq mi (&0000000000001426.0000001,426 km²) |  |
| Shelby County | 149 | Sidney | April 1, 1819 | Miami County | General Isaac Shelby (1750–1826), a Revolutionary War officer and Governor of Kentucky, | &0000000000047910.00000047,910 | &0000000000000409.270000409.27 sq mi (&0000000000001060.0000001,060 km²) |  |
| Stark County | 151 | Canton | February 13, 1808 | Columbiana County | General John Stark (1728–1822) , a Revolutionary War officer; known as the "Hero of Bennington" for his exemplary service at the Battle of Bennington in 1777 | &0000000000378098.000000378,098 | &0000000000000576.140000576.14 sq mi (&0000000000001492.0000001,492 km²) |  |
| Summit County | 153 | Akron | March 3, 1840 | Medina, Portage, and Stark Counties | Derived from having the highest elevation along the Ohio Canal | &0000000000542899.000000542,899 | &0000000000000412.720000412.72 sq mi (&0000000000001069.0000001,069 km²) |  |
| Trumbull County | 155 | Warren | July 10, 1800 | Jefferson and Wayne Counties | Jonathan Trumbull (1710-1785), Governor of Connecticut when the county was organized | &0000000000225116.000000225,116 | &0000000000000616.480000616.48 sq mi (&0000000000001597.0000001,597 km²) |  |
| Tuscarawas County | 157 | New Philadelphia | March 15, 1808 | Muskingum County | Tuscarawas River, meaning "open mouth river" or the Tuscarawas tribe who lived on the river | &0000000000090914.00000090,914 | &0000000000000567.580000567.58 sq mi (&0000000000001470.0000001,470 km²) |  |
| Union County | 159 | Marysville | April 1, 1820 | Delaware, Franklin, Logan, and Madison Counties | Named as such due to it formed by a union of four counties | &0000000000040909.00000040,909 | &0000000000000436.650000436.65 sq mi (&0000000000001131.0000001,131 km²) |  |
| Van Wert County | 161 | Van Wert | April 1, 1820 | Darke County | Isaac Van Wart (1760-1828), captor of spy John André during the Revolutionary War | &0000000000029659.00000029,659 | &0000000000000410.090000410.09 sq mi (&0000000000001062.0000001,062 km²) |  |
| Vinton County | 163 | McArthur | March 23, 1850 | Athens, Gallia, Hocking, Jackson, and Ross Counties | Samuel Finley Vinton (1792-1862), Ohio Statesman and U.S. Congressman | &0000000000012806.00000012,806 | &0000000000000414.080000414.08 sq mi (&0000000000001072.0000001,072 km²) |  |
| Warren County | 165 | Lebanon | May 1, 1803 | Hamilton County | General Joseph Warren (1741-1775), a Revolutionary War officer | &0000000000158383.000000158,383 | &0000000000000399.630000399.63 sq mi (&0000000000001035.0000001,035 km²) |  |
| Washington County | 167 | Marietta | July 27, 1788 | One of the original counties | George Washington (1732–1799), president of the Constitutional Convention | &0000000000063251.00000063,251 | &0000000000000635.150000635.15 sq mi (&0000000000001645.0000001,645 km²) |  |
| Wayne County | 169 | Wooster | March 1, 1808 | From non-county area | General Anthony Wayne (1745–1796), a Revolutionary War officer | &0000000000111564.000000111,564 | &0000000000000555.360000555.36 sq mi (&0000000000001438.0000001,438 km²) |  |
| Williams County | 171 | Bryan | April 1, 1820 | Darke County | David Williams (1754-1831), captor of spy John André during the Revolutionary War | &0000000000039188.00000039,188 | &0000000000000421.740000421.74 sq mi (&0000000000001092.0000001,092 km²) |  |
| Wood County | 173 | Bowling Green | April 1, 1820 | Refactored from non-county territory | Eleazer D. Wood (1783 -1814), founder of Fort Meigs | &0000000000121065.000000121,065 | &0000000000000617.320000617.32 sq mi (&0000000000001599.0000001,599 km²) |  |
| Wyandot County | 175 | Upper Sandusky | February 3, 1845 | Marion, Crawford, and Hardin Counties | Wyandot Indians | &0000000000022908.00000022,908 | &0000000000000405.610000405.61 sq mi (&0000000000001051.0000001,051 km²) |  |