| 1 | OSR | OSR | Belongs to SNCB | F | TRAFFIC |
| 2 | OSRB | OLSON, ROBERT TRUCKING | | | SCAC3 |
| 3 | OSRC | ON-STAGE RENTALS INC | | | SCAC4 |
| 4 | OSRK | OCHSNER TRUCKING | | | SCAC3 |
| 5 | OSRM | OSTEGO READY MIX INC | | | SCAC3 |
| 6 | OSRR | The Columbus & Ohio River R.R. Co. | added 10/1992 | | NAKINA |
| 7 | OSRR | Ohio Southern R.R., Inc. | 1/1994-7/2005 | | NAKINA |
| 8 | OSRR | Ohio R.R. System | eliminated 10/1992 | | NAKINA |
| 9 | OSRR | Ohio Southern R.R., Inc. | added 10/1987 | | NAKINA |
| 10 | OSRR | Ohio Southern R.R., Inc. | added 10/87 | | NRHS |
| 11 | OSRR | Ohio R.R. System | eliminated 10/92 | | NRHS |
| 12 | OSRR | The Columbus & Ohio River R.R. Co. | added 10/92 | | NRHS |
| 13 | OSRR | Ohio Southern R.R., Inc. | 1/94-7/2000 | | NRHS |
| 14 | OSRR | OHIO SOUTHERN RAILROAD INC. (COLUMBUS & OHIO RIVER RAILROAD CO.) | | | PWRC |
| 15 | OSRR | Ohio Southern Railroad | | | RSRV |
| 16 | OSRR | OHIO SOUTHERN RAILROAD CO | | | SCAC3 |
| 17 | OSRR | OHIO SOUTHERN RAILROAD CO | | | SCAC4 |
| 18 | OSRS | OVERLAND SHIPPERS & RECEIVERS ASSOC | | | SCAC3 |
| 19 | OSRT | OSBORNE, RON TRUCKING INC | | | SCAC3 |
| 20 | OSRU | SIEMENS ENERGY GLOBAL GMBH & CO. KG. | | D | BIC |
| 21 | OSRX | Ontario Southland Inc. | 7/2005 (not listed) | | NAKINA |
| 22 | OSRX | Ontario Southland Ry. Inc. | 7/2000 (not listed) | | NAKINA |
| 23 | OSRX | Oil State Refining Co. | 8/1920-7/1923 | | NAKINA |
| 24 | OSRX | Ontario Southland Ry. Inc. | Jul-00 | | NRHS |
| 25 | OSRX | *OIL STATE REFINING CO. | | | PWRC |
| 26 | OSRX | +ONTARIO SOUTHLAND RAILWAY | | | PWRC |
| 27 | OSRX | Ontario Southland Railway | | | RSRV |
| 28 | OSRX | ONTARIO SOUTHLAND INC | | | SCAC4 |
