Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Marco Millpond | Reservoir | 58 | Darlington | 34 16 37 N | 080 07 47 W |
| Marco Millpond | Reservoir | 56 | Lee | 34 16 35 N | 080 07 49 W |
| Marden Ranchettes | Populated Place | 97 | Sumter | 33 57 53 N | 080 29 56 W |
| Mare Branch | Stream | | Lexington | 33 49 49 N | 081 31 38 W |
| Mares Lake | Lake | 22 | Chesterfield | 34 36 49 N | 079 47 59 W |
| Margaret Hunter Park | Park | 151 | Newberry | 34 16 50 N | 081 37 32 W |
| Margate Swamp | Swamp | 23 | Berkeley | 33 26 01 N | 080 01 55 W |
| Margunart School (historical) | School | 101 | Edgefield | 33 36 39 N | 082 03 08 W |
| Maridell School (historical) | School | 320 | Greenville | 35 02 58 N | 082 25 14 W |
| Marietta | Populated Place | 305 | Greenville | 35 01 15 N | 082 30 05 W |
| Marigold Heights (subdivision) | Populated Place | 48 | Sumter | 33 54 53 N | 080 21 53 W |
| Marilyn Acres | Populated Place | 250 | Anderson | 34 33 05 N | 082 36 43 W |
| Marine Hospital (historical) | Hospital | 6 | Charleston | 32 46 41 N | 079 56 14 W |
| Marine Railway Pond Dam D-2942 | Dam | 3 | Beaufort | 32 17 19 N | 080 51 35 W |
| Mariners Cay Racquet and Yacht Club | Locale | 0 | Charleston | 32 39 44 N | 079 56 46 W |
| Mariners Watch | Populated Place | 9 | Beaufort | 32 23 01 N | 080 41 40 W |
| Marion | Populated Place | 22 | Marion | 34 10 42 N | 079 24 02 W |
| Marion Avenue Church of Christ | Church | 231 | Cherokee | 35 04 55 N | 081 39 12 W |
| Marion Baptist Church | Church | 21 | Marion | 34 10 40 N | 079 24 02 W |
| Marion Branch | Stream | | Greenwood | 34 09 11 N | 082 03 53 W |
| Marion Church of God | Church | 21 | Marion | 34 11 40 N | 079 23 50 W |
| Marion City Hall | Building | 22 | Marion | 34 10 39 N | 079 24 01 W |
| Marion County | Civil | 15 | Marion | 34 05 01 N | 079 25 59 W |
| Marion County Airport | Airport | 27 | Marion | 34 10 52 N | 079 20 04 W |
| Marion County Courthouse | Building | 22 | Marion | 34 10 44 N | 079 24 02 W |
| Marion County Jail | Building | 22 | Marion | 34 10 19 N | 079 24 03 W |
| Marion County Library | Building | 22 | Marion | 34 10 41 N | 079 23 57 W |
| Marion County Training School (historical) | School | 22 | Marion | 34 10 19 N | 079 23 46 W |
| Marion Creek | Stream | | Greenwood | 34 08 16 N | 082 02 15 W |
| Marion Davis Park | Park | 149 | Newberry | 34 17 38 N | 081 37 54 W |
| Marion Elementary School | School | 21 | Marion | 34 10 44 N | 079 24 17 W |
| Marion Gresham Lookout Tower | Tower | 15 | Marion | 34 06 15 N | 079 24 08 W |
| Marion High School | School | 21 | Marion | 34 11 04 N | 079 24 02 W |
| Marion Historic District | Park | 22 | Marion | 34 10 49 N | 079 24 01 W |
| Marion Mall Shopping Center | Locale | 21 | Marion | 34 10 47 N | 079 22 57 W |
| Marion Memorial Hospital | Hospital | 21 | Marion | 34 11 31 N | 079 23 50 W |
| Marion Post Office | Post Office | 21 | Marion | 34 10 60 N | 079 23 59 W |
| Marion Presbyterian Church | Church | 21 | Marion | 34 10 35 N | 079 24 03 W |
| Marion School | School | 19 | Williamsburg | 33 32 28 N | 079 49 46 W |
| Marion Sims Memorial Hospital | Hospital | 149 | Lancaster | 34 43 08 N | 080 47 17 W |
| Marion Square | Park | 6 | Charleston | 32 47 13 N | 079 56 08 W |
| Marion Street Church | Church | 155 | Aiken | 33 33 23 N | 081 42 38 W |
| Marit Cemetery | Cemetery | 243 | Oconee | 34 34 52 N | 083 02 44 W |
| Mark Bay | Bay | -5 | Charleston | 32 53 05 N | 079 40 56 W |
| Mark Island | Populated Place | 3 | Beaufort | 32 28 28 N | 080 40 06 W |
| Market Place Shopping Center | Locale | 238 | Anderson | 34 32 54 N | 082 40 17 W |
| Market Place Shopping Center | Locale | 70 | Richland | 34 00 11 N | 081 01 05 W |
| Marks Creek | Stream | 27 | Marlboro | 34 47 35 N | 079 55 55 W |
| Marks School | School | 42 | Florence | 34 09 08 N | 079 52 56 W |
| Marlboro | Populated Place | 26 | Marlboro | 34 32 13 N | 079 43 57 W |
| Marlboro Academy | School | 61 | Marlboro | 34 39 46 N | 079 38 06 W |
| Marlboro County | Civil | 41 | Marlboro | 34 35 01 N | 079 39 59 W |
| Marlboro County Airport | Airport | 44 | Marlboro | 34 37 21 N | 079 44 05 W |
| Marlboro County Courthouse | Building | 50 | Marlboro | 34 37 01 N | 079 40 05 W |
| Marlboro County General Hospital | Hospital | 43 | Marlboro | 34 37 07 N | 079 41 02 W |
| Marlboro County Industrial and High School (historical) | School | 47 | Marlboro | 34 37 47 N | 079 40 30 W |
| Marlboro County Public Library | Building | 48 | Marlboro | 34 37 03 N | 079 40 57 W |
| Marlboro School | School | 46 | Marlboro | 34 36 34 N | 079 41 32 W |
| Marlborough (subdivision) | Populated Place | 2 | Charleston | 32 45 27 N | 079 58 48 W |
| Marlin Estates | Populated Place | 22 | Dorchester | 32 59 31 N | 080 11 42 W |
| Marlowe Cemetery | Cemetery | 10 | Horry | 34 01 04 N | 078 44 15 W |
| Marlowe Creek | Stream | | Lexington | 33 51 47 N | 081 28 05 W |
| Marqurt Landing (historical) | Locale | 57 | Edgefield | 33 34 23 N | 082 03 51 W |
| Marrington Plantation | Locale | 4 | Berkeley | 32 58 23 N | 079 57 05 W |
| Marritt Pond | Reservoir | 258 | Oconee | 34 41 22 N | 083 04 23 W |
| Marrow Bone Creek | Stream | | Greenville | 34 46 34 N | 082 21 29 W |
| Marrow Bone Swamp Creek | Stream | | Aiken | 33 43 50 N | 081 24 39 W |
| Mars Bluff | Cliff | 23 | Florence | 34 11 34 N | 079 34 16 W |
| Mars Bluff | Populated Place | 30 | Florence | 34 12 20 N | 079 39 19 W |
| Mars Bluff Bridge | Bridge | 10 | Florence | 34 11 25 N | 079 34 11 W |
| Mars Bluff Church | Church | 31 | Florence | 34 13 05 N | 079 37 06 W |
| Mars Bluff Firetower | Locale | 30 | Florence | 34 11 30 N | 079 37 37 W |
| Mars Bluff School | School | 30 | Florence | 34 11 13 N | 079 39 26 W |
| Mars Branch | Swamp | 26 | Allendale | 32 56 08 N | 081 26 47 W |
| Mars Bridge | Bridge | 105 | McCormick | 34 00 48 N | 082 27 55 W |
| Mars Hill Church | Church | 189 | Greenwood | 34 14 40 N | 082 13 20 W |
| Marsh Cemetery | Cemetery | 201 | Edgefield | 33 45 19 N | 081 52 12 W |
| Marsh Cemetery | Cemetery | 201 | Edgefield | 33 45 26 N | 081 52 08 W |
| Marsh Cove | Populated Place | 5 | Charleston | 32 49 01 N | 080 01 42 W |
| Marsh Creek | Stream | | Marion | 33 57 51 N | 079 20 08 W |
| Marsh Harbor | Populated Place | 3 | Beaufort | 32 26 54 N | 080 39 22 W |
| Marsh Hawk | Populated Place | 8 | Beaufort | 32 28 49 N | 080 38 27 W |
| Marsh Island | Island | -3 | Beaufort | 32 29 28 N | 080 30 10 W |
| Marsh Island | Island | 1 | Georgetown | 33 16 43 N | 079 13 51 W |
| Marsh Island Spit | Bar | -3 | Beaufort | 32 29 17 N | 080 29 49 W |
| Marsh Islands | Island | -25 | Georgetown | 33 16 58 N | 079 13 45 W |
| Marsh Point | Populated Place | 4 | Charleston | 32 44 13 N | 079 55 02 W |
| Marsh Point Airport | Airport | 3 | Beaufort | 32 27 43 N | 080 36 03 W |
| Marsh Pond | Lake | 5 | Dorchester | 32 57 12 N | 080 17 40 W |
| Marshall Bible Way Holiness Church | Church | 33 | Dillon | 34 24 48 N | 079 22 18 W |
| Marshall Branch | Stream | | Dorchester | 33 08 55 N | 080 21 16 W |
| Marshall Cemetery | Cemetery | 41 | Sumter | 33 51 06 N | 080 19 53 W |
| Marshall Chapel | Church | 149 | Greenwood | 34 08 48 N | 082 03 45 W |
| Marshall Chapel School (historical) | School | 146 | Greenwood | 34 08 45 N | 082 03 40 W |
| Marshall Elementary School | School | 85 | Orangeburg | 33 31 12 N | 080 51 37 W |
| Marshall Forest | Populated Place | 275 | Greenville | 34 48 40 N | 082 22 23 W |
| Marshall Heights (subdivision) | Populated Place | 77 | Orangeburg | 33 31 15 N | 080 51 49 W |
| Marshall Heights (subdivision) | Populated Place | 316 | Pickens | 34 50 10 N | 082 36 24 W |
| Marshall Memorial Church | Church | 237 | Anderson | 34 27 22 N | 082 39 40 W |
| Marshall Park | Park | 79 | Richland | 34 01 12 N | 081 03 01 W |
| Marshall School | School | 263 | Anderson | 34 31 23 N | 082 30 09 W |
| Marshalls Church | Church | 96 | Kershaw | 34 16 48 N | 080 25 57 W |
| Marsnip Branch | Stream | | Marlboro | 34 39 59 N | 079 34 20 W |
| Marsuella School (historical) | School | 173 | Aiken | 33 46 03 N | 081 38 24 W |
| Martha Law Estates (subdivision) | Populated Place | 22 | Florence | 33 51 34 N | 079 43 44 W |
| Martha Law Municipal Park | Park | 22 | Florence | 33 51 45 N | 079 43 39 W |
| Martha Shands Branch | Stream | | Spartanburg | 34 45 50 N | 081 53 41 W |
| Marthas Chapel (historical) | Church | 131 | McCormick | 33 51 56 N | 082 22 25 W |
| Marthas Chapel School (historical) | School | 127 | McCormick | 33 52 17 N | 082 22 50 W |
| Martin | Populated Place | 28 | Allendale | 33 04 09 N | 081 28 35 W |