| 1 | SIL | Sea Island Air Ltd. | Callsign: Seaisle, | CDN | AVCODES |
| 2 | SIL | Servicios Aeronauticos Integrales, S de R.L. | Callsign: Servicios Intergrales, | MEX | AVCODES |
| 3 | SIL | Silver Airways LLC | IATA: 3M, Callsign: Silver Wings, IATA Prefix: 449, Name changed to Silver Airways Corp. Formed from the bankrupt assets of Gulfstream International Airlines. | USA | AVCODES |
| 4 | SIL | Silver Airways Corp. | IATA: 3M, Callsign: Silver Wings, IATA Prefix: 449, Name changed from Silver Airways LLC. Formed from the bankrupt assets of Gulfstream International Airlines. | USA | AVCODES |
| 5 | SIL | Servicios Aeronauticos Integrales | | | ICAO1 |
| 6 | SIL | SEASPAN INTERNATIONAL | | | PWRC |
| 7 | SILA | Silverton Rail | | AUS | TRAFFIC |
| 8 | SILB | SIM LABEL INC | | | SCAC4 |
| 9 | SILB | Silbernagl | City: Castelrotto | I | TRAFFIC |
| 10 | SILC | SILVER STATE COACH | | | SCAC4 |
| 11 | SILD | SIMON, DICK, TRUCKING, INC | | | SCAC1 |
| 12 | SILD | Dick Simon Trucking Inc. | | USA | TRAFFIC |
| 13 | SILE | SILEX ELEV. AND TRUCKING, INC | | | SCAC1 |
| 14 | SILF | S.I.L.F. S.p.A., Bari | | I | TRAFFIC |
| 15 | SILG | STILLWATER TRANSPORT, LLC | | | SCAC4 |
| 16 | SILN | SOUTHERN INTERMODAL INC | | | SCAC4 |
| 17 | SILP | SILVER OAK PERCHERONS | | | SCAC4 |
| 18 | SILR | SINICWAY INTERNATIONAL LOGISTICS LT | | | SCAC4 |
| 19 | SILU | SUN INTERMODAL LIMITED | | GB | BIC |
| 20 | SILU | SUTTONS INTERNATIONAL | | | PWRC |
| 21 | SILU | Suttons International | | | RSRV |
| 22 | SILV | Silverlink Train Services Ltd. | Real: SL, 1999: 282km standard gauge, electrified at 25kV 50Hz and 750V= 3rd rail Silverlink Trains is a regional franchise in the British railway system with routes in suburban London and from London to Northampton. It is owned by National Express Group plc. | GB | TRAFFIC |
| 23 | SILW | SILVER WOLF FREIGHTWAYS INC | | | SCAC4 |
| 24 | SILX | The Silurian Oil Co. | 7/1930-7/1932 | | NAKINA |
| 25 | SILX | The Silurian Oil Co. (W.C. McBride, Inc.) | 7/1935 | | NAKINA |
| 26 | SILX | W.C. McBride, Inc. | 7/1937-1/1941 | | NAKINA |
| 27 | SILX | Southern Indiana Liquified Gas Co. | 1/1950 | | NAKINA |
| 28 | SILX | Jeffersonville Silgas, Inc. | 1/1952-10/1966; eliminated 10/1969 | | NAKINA |
| 29 | SILX | S & I Locomotive Services, Inc. | 7/2005 (not listed) | | NAKINA |
| 30 | SILX | The Silurian Oil Co. (W.C. McBride, Inc.) | Apr-38 | | NRHS |
| 31 | SILX | Jeffersonville Silgas, Inc. | 1/52-10/66; eliminated 10/69 | | NRHS |
| 32 | SILX | *W. C. MCBRIDE, INC. [SILURIAN OIL CO.] | | | PWRC |
| 33 | SILX | *JEFFERSON SILGAS, INC. [SOUTYHERN INDIANA LIQUIFIED GAS CO.] | | | PWRC |
| 34 | SILX | +S & I LOCOMOTIVE SERVICES, INC. | | | PWRC |
| 35 | SILX | S and I Locomotive Services | | | RSRV |
| 36 | SILX | S & I LOCOMOTIVE SERVICES INC | | | SCAC4 |
| 37 | SILZ | SISSETON LINE ASSOCIATION | | | PWRC |
