| Code | Name | Region |
|---|---|---|
| CASUZ | Summerland | BC |
| CASUM | Summerside | PE |
| CAIUM | Summit Lake | BC |
| CASPK | Sun Peaks | BC |
| CASDL | Sunderland | ON |
| CASDR | Sundre | AB |
| CASUK | Sunnybrook | AB |
| CASYS | Sunnyside | NL |
| CASUY | Surrey | BC |
| CASUS | Sussex | NB |
| CASXE | Sussex Corner | NB |
| CAUTT | Sutton | ON |
| CASUT | Sutton | QC |
| CASYT | Stoney Point, Essex | ON |
| CASYM | Stony Mountain | MB |
| CASYP | Stony Plain | AB |
| CAYSF | Stony Rapids | SK |
| CASMT | Stormont | NS |
| CASFV | Stouffville | ON |
| CASFL | Straffordville | ON |
| CASBQ | Strasbourg | SK |
| CASTR | Stratford | ON |
| CASTF | Stratford | PE |
| CASRF | Stratford | QC |
| CASCR | Strathclair | MB |
| CASCN | Strathcona | AB |
| CASOE | Strathmore | AB |
| CAS2V | Strathnaver | BC |
| CASTT | Strathroy | ON |
| CASVI | Streetsville | ON |
| CASFS | Strongfield | SK |
| CASIA | Sts-anges | QC |
| CAYRR | Stuart Island | BC |
| CASVY | Stavely | AB |
| CASTY | Stayner | ON |
| CASME | Steelman | SK |
| CASTB | Steinbach | MB |
| CASTN | Stellarton | NS |
| CASP5 | Stephenfield | MB |
| CASTV | Stephenville | NL |
| CASER | Stettler | AB |
| CASVS | Stevensville | ON |
| CASVN | Steveston | BC |
| CASTW | Stewart | BC |
| CASWE | Stewiacke | NS |
| CASLG | Stirling | ON |
| CASLL | Stittsville | ON |
| CASTK | Stockton | MB |
| CA7TK | Stoke | QC |
| CASOA | Stoneham | QC |