S
| Railway name | Locale | Operating years | Comments |
|---|---|---|---|
| St. Eustache Railway | Acquired by CPR. | ||
| St. John and Quebec Railway | Acquired by CNR. | ||
| St. Lawrence and Atlantic Railroad | southwestern Quebec | 1853-1853 | Acquired by GTR. |
| St. Lawrence and Hudson Railway | Ontario, Quebec, New England | 1996–2001 | Subsidiary of CPR created to operate lines in eastern North America. Merged back into parent company. |
| St. Lawrence and Ottawa Railway | Acquired by CPR. | ||
| St. Mary's and Western Railway | Acquired by CPR. | ||
| St. Maurice Valley Railway | Acquired by CPR. | ||
| Schomberg and Aurora Railway | |||
| Shawinigan Falls Terminal Railway | |||
| Smoky Falls Railway | Subsidiary of SFPPC. | ||
| South Ontario Pacific Railway | Acquired by CPR. | ||
| South Western Traction Company | Ontario | 1902–1908 | Became London and Lake Erie Railway and Transportation Company. |
| Sydney and Louisburg Railway | Cape Breton Island | 1895–1966 | Acquired by DEVCO. |
Read more about this topic: List Of Defunct Canadian Railways