Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Orangeburg National Fish Hatchery | Locale | 51 | Orangeburg | 33 28 05 N | 080 51 27 W |
| Orangeburg Post Office | Post Office | 56 | Orangeburg | 33 29 39 N | 080 52 02 W |
| Orangeburg-Calhoun Law Enforcement Center | Building | 81 | Orangeburg | 33 30 43 N | 080 51 08 W |
| Orangeburg-Calhoun Regional Hospital | Hospital | 95 | Orangeburg | 33 32 25 N | 080 49 50 W |
| Orangeburg-Calhoun Technical College | School | 99 | Orangeburg | 33 32 44 N | 080 49 44 W |
| Orangeburg-Wilkinson School | School | 78 | Orangeburg | 33 30 28 N | 080 51 57 W |
| Orangegrove Creek | Stream | | Charleston | 32 47 57 N | 079 58 33 W |
| Orangewood (subdivision) | Populated Place | 59 | Orangeburg | 33 28 47 N | 080 48 41 W |
| Oratory School for Boys (historical) | School | 204 | York | 34 56 15 N | 081 01 28 W |
| Orchard Acres | Populated Place | 296 | Greenville | 34 54 29 N | 082 19 20 W |
| Orchard Branch | Stream | | Oconee | 34 48 18 N | 083 09 54 W |
| Orchard Hill | Populated Place | 22 | Dorchester | 33 01 32 N | 080 13 21 W |
| Orchard Park | Populated Place | 321 | Greenville | 34 51 15 N | 082 19 24 W |
| Original Free Will Baptist Church | Church | 43 | Florence | 34 11 42 N | 079 47 42 W |
| Orleans Estates (subdivision) | Populated Place | 6 | Charleston | 32 47 49 N | 080 01 37 W |
| Orleans Plaza Shopping Center | Locale | 3 | Beaufort | 32 09 21 N | 080 45 34 W |
| Orleans Woods (subdivision) | Populated Place | 6 | Charleston | 32 48 13 N | 080 01 29 W |
| Ormand Hall Creek | Stream | | Charleston | 33 06 39 N | 079 23 10 W |
| Oro Church | Church | 153 | Chesterfield | 34 46 53 N | 080 18 53 W |
| Oro School (historical) | School | 143 | Chesterfield | 34 46 47 N | 080 18 44 W |
| Orphanage Branch | Stream | | Richland | 34 00 50 N | 080 59 13 W |
| Orr Mill Park | Park | 238 | Anderson | 34 29 07 N | 082 39 08 W |
| Orr Swamp | Swamp | 18 | Williamsburg | 33 42 21 N | 079 40 59 W |
| Orrs | Populated Place | 148 | Chester | 34 43 02 N | 081 07 24 W |
| Orrs Church | Church | 146 | Chester | 34 43 18 N | 081 08 59 W |
| Orrs Mill Creek | Stream | | Oconee | 34 52 17 N | 083 08 08 W |
| Orrville Cemetery | Cemetery | 227 | Anderson | 34 29 26 N | 082 39 15 W |
| Orrville Church | Church | 247 | Anderson | 34 28 52 N | 082 38 53 W |
| Orrville United Methodist Church | Church | 246 | Anderson | 34 28 59 N | 082 38 51 W |
| Orum | Populated Place | 29 | Florence | 34 04 56 N | 079 34 05 W |
| Osborn | Populated Place | 14 | Charleston | 32 45 21 N | 080 20 46 W |
| Osborn Branch | Stream | | Chester | 34 47 34 N | 081 27 15 W |
| Osborn Church | Church | 11 | Charleston | 32 45 56 N | 080 21 37 W |
| Osborne Administration Building | Building | 97 | Richland | 33 59 58 N | 081 01 39 W |
| Osborne Mountain | Summit | 604 | Greenville | 35 07 39 N | 082 30 43 W |
| Oscar Street School (historical) | School | 293 | Greenville | 34 51 15 N | 082 24 36 W |
| Osceola Church | Church | 180 | Lancaster | 34 54 25 N | 080 48 35 W |
| Osceola Heights (subdivision) | Populated Place | 1 | Charleston | 32 47 13 N | 079 51 33 W |
| Osceola Oaks (subdivision) | Populated Place | 4 | Charleston | 32 47 18 N | 079 51 41 W |
| Osceola School (historical) | School | 186 | Lancaster | 34 54 25 N | 080 48 31 W |
| Oswald Field | Airport | 61 | Allendale | 32 59 43 N | 081 20 47 W |
| Oswald Park | Populated Place | 122 | Lexington | 34 02 07 N | 081 24 48 W |
| Oswald Place | Populated Place | 3 | Charleston | 32 43 11 N | 079 56 18 W |
| Oswald Pond | Reservoir | 134 | Lexington | 33 58 38 N | 081 16 51 W |
| Oswalds Pond | Reservoir | 142 | Lexington | 33 53 55 N | 081 23 35 W |
| Oswalds Pond Dam D-2565 | Dam | 50 | Allendale | 32 59 49 N | 081 19 47 W |
| Oswego | Populated Place | 47 | Sumter | 34 00 27 N | 080 17 15 W |
| Oswego School (historical) | School | 47 | Sumter | 34 00 26 N | 080 17 10 W |
| Othello Church | Church | 22 | Florence | 34 01 20 N | 079 44 16 W |
| Othello School | School | 22 | Florence | 34 01 27 N | 079 44 14 W |
| Otranto | Populated Place | 12 | Charleston | 32 57 55 N | 080 02 39 W |
| Otranto Plaza Shopping Center | Locale | 11 | Charleston | 32 58 01 N | 080 02 36 W |
| Ott (historical) | Populated Place | 70 | Bamberg | 33 18 46 N | 081 05 36 W |
| Ott Cemetery | Cemetery | 35 | Orangeburg | 33 15 03 N | 080 50 01 W |
| Ott Shoals | Rapids | 183 | Spartanburg | 34 48 04 N | 081 57 57 W |
| Otter Creek | Channel | 2 | Colleton | 32 28 53 N | 080 24 04 W |
| Otter Creek | Stream | | Lancaster | 34 48 05 N | 080 34 22 W |
| Otter Creek | Stream | | Oconee | 34 47 11 N | 083 08 07 W |
| Otter Hole | Populated Place | 3 | Beaufort | 32 11 43 N | 080 44 01 W |
| Otter Islands | Island | 2 | Colleton | 32 29 02 N | 080 24 10 W |
| Otter Lake | Lake | 25 | Orangeburg | 33 20 12 N | 080 31 09 W |
| Otter Lake | Lake | 36 | Richland | 34 04 25 N | 080 39 26 W |
| Otterslide Branch | Stream | | Kershaw | 34 06 50 N | 080 42 19 W |
| Otterson Fort Cemetery | Cemetery | 99 | Union | 34 34 40 N | 081 34 34 W |
| Otts Pond | Reservoir | 96 | Calhoun | 33 42 43 N | 080 55 53 W |
| Otts Pond Dam D-2677 | Dam | 96 | Calhoun | 33 42 43 N | 080 55 53 W |
| Our Chapel | Church | 6 | Charleston | 33 03 22 N | 079 33 25 W |
| Our Lady of Lourdes Catholic Church | Church | 186 | Greenwood | 34 12 40 N | 082 09 48 W |
| Our Lady of Mepkin Monastery | Church | 9 | Berkeley | 33 06 39 N | 079 56 34 W |
| Our Lady of Mercy Convent | Church | 6 | Charleston | 32 46 38 N | 079 56 04 W |
| Our Lady of Mercy Roman Catholic Church | Church | 4 | Charleston | 32 47 49 N | 079 56 12 W |
| Our Lady of Perpetual Help Roman Catholic Church | Church | 69 | Kershaw | 34 15 35 N | 080 36 17 W |
| Our Lady of the Rosary Catholic Church | Church | 277 | Greenville | 34 47 57 N | 082 22 49 W |
| Our Lady Star of the Sea Church | Church | 7 | Horry | 33 50 04 N | 078 40 14 W |
| Ousley Dale Church | Church | 115 | Chesterfield | 34 30 13 N | 080 05 07 W |
| Ousley Dale School (historical) | School | 114 | Chesterfield | 34 30 13 N | 080 05 05 W |
| Ousleydale School (historical) | School | 117 | Chesterfield | 34 30 28 N | 080 04 43 W |
| Outing Lake | Reservoir | 97 | Aiken | 33 35 42 N | 081 45 47 W |
| Outland | Populated Place | 19 | Williamsburg | 33 43 37 N | 079 22 21 W |
| Outlet Park at Waccamaw Shopping Center | Locale | 6 | Horry | 33 42 55 N | 078 55 35 W |
| Outlet Pointe Shopping Center | Locale | 71 | Lexington | 34 01 53 N | 081 07 26 W |
| Outside Swamp | Swamp | 5 | Horry | 33 51 15 N | 078 51 32 W |
| Outz Store (historical) | Locale | 152 | Greenwood | 33 58 51 N | 082 00 32 W |
| Overbrook | Populated Place | 296 | Greenville | 34 51 35 N | 082 22 40 W |
| Overbrook Cemetery | Cemetery | 143 | McCormick | 33 55 31 N | 082 16 55 W |
| Overbrook Child Development Center | School | 284 | Greenville | 34 51 11 N | 082 22 48 W |
| Owdoms | Populated Place | 167 | Saluda | 33 59 04 N | 081 52 46 W |
| Owens | Populated Place | 12 | Georgetown | 33 41 37 N | 079 23 06 W |
| Owens | Populated Place | 7 | Horry | 33 41 24 N | 078 54 19 W |
| Owens (historical) | Populated Place | 189 | Laurens | 34 24 54 N | 082 10 05 W |
| Owens Cemetery | Cemetery | 139 | Fairfield | 34 15 40 N | 081 16 50 W |
| Owens Cemetery | Cemetery | 22 | Florence | 33 47 47 N | 079 28 58 W |
| Owens Chapel | Church | 244 | Oconee | 34 46 34 N | 082 55 40 W |
| Owens Crossroad | Populated Place | 73 | Barnwell | 33 09 25 N | 081 24 03 W |
| Owens Field Airport | Airport | 58 | Richland | 33 58 26 N | 081 00 04 W |
| Owens Pond | Reservoir | 53 | Orangeburg | 33 28 13 N | 080 47 05 W |
| Owens Pond D-3067 Dam | Dam | 39 | Barnwell | 33 10 37 N | 081 27 35 W |
| Owings | Populated Place | 257 | Laurens | 34 37 51 N | 082 08 00 W |
| Owl Branch | Stream | | Edgefield | 33 43 00 N | 082 05 12 W |
| Ox Swamp | Stream | | Clarendon | 33 41 58 N | 080 11 30 W |
| Ox Swamp | Stream | | Williamsburg | 33 33 47 N | 079 43 43 W |
| Oxford | Populated Place | 262 | Oconee | 34 44 10 N | 082 56 30 W |
| Oxford Acres | Populated Place | 281 | Greenville | 34 47 58 N | 082 26 59 W |
| Oxpen Branch | Stream | | Chesterfield | 34 35 52 N | 080 16 21 W |
| Oxpen Lake Dam D-3193 | Dam | 119 | Chesterfield | 34 36 25 N | 080 14 59 W |
| Oyster Bank | Bar | -10 | Beaufort | 32 26 08 N | 080 27 39 W |
| Oyster Bay | Bay | -2 | Charleston | 33 03 48 N | 079 26 00 W |
| Oyster Bay | Bay | -7 | Georgetown | 33 18 19 N | 079 11 38 W |
| Oyster House Creek | Stream | | Charleston | 32 41 57 N | 080 13 14 W |
| Oyster Point | Cape | 8 | Charleston | 32 46 10 N | 079 55 44 W |