| County | Date Formed | Parent County | County Seat |
|---|
| Anderson | 1801 | Knox, Grainger | Clinton |
| Bedford | 1807 | Rutheford, Indian Lands | Shelbyville |
| Benton | 1835 | Humphreys | Camden |
| Bledsoe | 1807 | Roane, Indian Lands | Pikeville |
| Blount | 1795 | Knox | Maryville |
| Bradley | 1836 | Indian Lands | Cleveland |
| Campbell | 1806 | Anderson, Claiborne | Jacksboro |
| Cannon | 1836 | Rutherford, Smith, Warren | Woodbury |
| Carroll | 1821/1822 | Indian Lands | Huntingdon |
| Carter | 1796 | Washington | Elizabethton |
| Cheatham | 1856 | Davidson, Dickson & Montgomery | Ashland City |
| Chester | 1879 | Hardeman, Henderson, McNairy, Madison | Henderson |
| Claiborne | 1801 | Grainger, Hawkins | Tazewell |
| Clay | 1870 | Jackson, Overton | Celina |
| Cocke | 1797 | Jefferson | Newport |
| Coffee | 1836 | Bedford, Franklin, Warren | Manchester |
| Crockett | 1871 | Dyer, Gibson, Haywood, Madison | Alamo |
| Cumberland | 1855/56 | Bledsoe, Fentress, Morgan, Putnam, Rhea, White | Crossville |
| Davidson | 1783 | Cumberland District of North Carolina, Washington County | Nashville |
| Decatur | 1845/46 | Perry | Decaturville |
| DeKalb | 1837/38 | Cannon, Jackson, Warren, White | Smithville |
| Dickson | 1803 | Montgomery, Robertson | Charlotte |
| Dyer | 1823 | Indian Lands | Dyersburg |
| Fayette | 1824 | Indian Lands | Somerville |
| Fentress | 1823 | Morgan, Overton, White | Jamestown |
| Franklin | 1807 | Rutherford, Indian Lands | Winchester |
| Gibson | 1823 | Indian Lands | Trenton |
| Giles | 1809, 1810 | Indian Lands | Pulaski |
| Grainger | 1796 | Hawkins | Rutledge |
| Greene | 1783 | Washington | Greeneville |
| Grundy | 1844 | Coffee, Franklin, Warren | Altamont |
| Hamblen | 1870 | Jefferson, Grainger, Greene | Morriwstown |
| Hamilton | 1819 | Rhea | Dallas (up to 1840) Chattanooga (1870-present) |
| Hancock | 1844 | Hawkins, Claiborne | Sneedville |
| Hardeman | 1823 | Hardin, Indian Lands | Bolivar (known as Big Hatchie before 1824) |
| Hardin | 1819/1820 | Indian Lands | Hardinsville (1820-30), Savannah (1830- date) |
| Hawkins | 1786 | Sullivan | Rogersville |
| Haywood | 1823 | Indian Lands | Brownsville |
| Henderson | 1821 | Indian Lands | Lexington |
| Henry | 1821 | Indian Lands | Paris |
| Hickman | 1807 | Dickson | Vernon (1810-22) |
| Houston | 1871 | Stewart, Humphreys, Dickson, Montgomery | Arlington (1872-78), Erin (1878-present) |
| Humphreys | 1809 | Stewart | Reynoldsburg (1812-36), Waverly (1836-present) |
| Jackson | 1801 | Smith, Indian Lands | Fort Blount (1892-06), Williamsburg (1806-1819), Gainesboro (1819-present) |
| James | 1871 | Bradley | Ooltewah |
| Jefferson | 1792 | Hawkins, Greene | Dandridge |
| Johnson | 1836 | Carter | Mountain City (known as Taylorsville pre-Civil War) |
| Knox | 1792 | Greene, Hawkins | Knoxville |
| Lake | 1870 | Obion | Tiptonville |
| Lauderdale | 1835 | Haywood, Dyer, Tipton | Ripley |
| Lawrence | 1817 | Hickman, Indian Lands | Lawrenceburg |
| Lewis | 1843/44 | Hickman, Lawrence, Maury, Wayne | Gordon (1844-48), Newberry (1848-97), Hohenwald (1897-present) |
| Lincoln | 1809 | Bedford | Fayetteville |
| Loudon | 1870 | Blount, Monroe, Roane, McMinn | Loudon |
| Macon | 1842 | Smith, Sumner | Lafayette |
| Madison | 1821 | Indian Lands | Jackson |
| Marion | 1817 | Indian Lands | Cheekville (1818-20), Jasper (1820-present) |
| Marshall | 1836 | Bedford, Giles, Lincoln, Maury | Lewisburg |
| Maury | 1807 | Williamson, Indian Lands | Columbia |
| McMinn | 1819 | Indian Lands | Calhoun (1820-23), Athens (1823-present) |
| McNairy | 1823 | Hardin | Purdy (1824-90), Selmer (1890-date) |
| Meigs | 1836 | Rhea | Decatur |
| Monroe | 1819 | Indian Lands | Morganton (1820-22), Madisonville (1822-present) |
| Montgomery | 1796 | Tennessee (abolished in 1796) | Clarksville |
| Moore | 1871 | Bedford, Franklin, Lincoln | Lynchburg |
| Morgan | 1817 | Roane, Anderson | Montgomery (1818-70), Wartburg (1870-present) |
| Obion | 1823 | Indian Lands | Troy (1824-1890), Union City (1890-present) |
| Overton | 1806 | Jackson, Indian Lands | Monroe (1810-35), Livingston (1835-present) |
| Perry | 1819 | Humphreys, Hickman | Perryville (1821-46), Bethel (Harrisburg) (1846-48), Linden (1848-present) |
| Pickett | 1879 | Fentress | Smyrna |
| Polk | 1839 | Bradley, McMinn | Benton |
| Putnam | 1842 (abolished and re-established 1854) | Fentress, Jackson, Overton, Smith, White | Cookeville |
| Rhea | 1807 | Roane | Dayton |
| Roane | 1801 | Knox, Indian Lands | Kingston |
| Robertson | 1796 | Tennessee, Sumner | Springfield |
| Rutherford | 1803 | Davidson, Williamson, Wilson | Murfreesboro |
| Scott | 1849 | Anderson, Campbell, Fentress, Morgan | Huntsville |
| Sequatchie | 1857 | Hamilton, Marion, Warren | Dunlap |
| Sevier | 1794 | Jefferson | Sevierville |
| Shelby | 1819 | Indian Lands | Memphis |
| Smith | 1799 | Sumner, Indian Lands | Carthage |
| Stewart | 1803 | Montgomery | Dover |
| Sullivan | 1779 | Washington | Blountville |
| Sumner | 1786 | Davidson | Gallatin |
| Tipton | 1823 | Indian Lands | Covington |
| Trousdale | 1870 | Macon, Smith, Sumner, Wilson | Hartsville |
| Unicoi | 1875 | Carter, Washington | Erwin |
| Union | 1850 | Anderson, Cambpell, Claiborne, Grainger, Knox | Maynardville |
| VanBuren | 1840 | White, Warren | Spencer |
| Warren | 1807/08 | White, Jackson, Smith, Indian Lands | McMinnville |
| Washington | 1777 | Washington District, North Carolina | Jonesborough |
| Wayne | 1817 | Hickman | Waynesboro |
| Weakley | 1823 | Indian Lands | Dresden |
| White | 1806 | Jackson, Smith | Sparta |
| Williamson | 1799 | Davidson | Franklin |
| Wilson | 1799 | Sumner | Lebanon |
