| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sadberis | city | Ontario | Canada | 46.50 | -80.97 | 898 | 25707 |
| Saint Albert | city | Ontario | Canada | 45.26 | -75.12 | 203 | 2202 |
| Saint Anns | city | Ontario | Canada | 43.08 | -79.50 | 830 | 8215 |
| Saint Catharines | city | Ontario | Canada | 43.17 | -79.23 | 337 | 99048 |
| Saint Catherines | city | Ontario | Canada | 43.17 | -79.23 | 337 | 99048 |
| Saint Clair Beach | city | Ontario | Canada | 42.32 | -82.85 | 830 | 25391 |
| Saint Clements | city | Ontario | Canada | 43.52 | -80.65 | 1197 | 8288 |
| Saint George | city | Ontario | Canada | 43.25 | -80.25 | 830 | 3991 |
| Saint Isidore de Prescott | city | Ontario | Canada | 45.39 | -74.91 | 203 | 1593 |
| Saint Jacobs | city | Ontario | Canada | 43.54 | -80.55 | 1099 | 28459 |
| Saint Marys | city | Ontario | Canada | 43.25 | -81.13 | 1026 | 8933 |
| Saint Thomas | city | Ontario | Canada | 42.78 | -81.19 | 830 | 37453 |
| Saint Williams | city | Ontario | Canada | 42.67 | -80.42 | 830 | 1412 |
| Saint-Charles | city | Ontario | Canada | 46.35 | -80.42 | 830 | 351 |
| Saint-Eugene | city | Ontario | Canada | 45.51 | -74.47 | 173 | 1043 |
| Sand Lake | city | Ontario | Canada | 47.76 | -84.50 | 1669 | 0 |
| Sandwich | city | Ontario | Canada | 42.28 | -83.07 | 830 | 118980 |
| Sandwich | city | Ontario | Canada | 42.30 | -83.07 | 830 | 157592 |
| Sandy Lake | city | Ontario | Canada | 53.03 | -93.23 | 892 | 12 |
| Sankta Katarino | city | Ontario | Canada | 43.17 | -79.23 | 337 | 99048 |
| Sarawak | city | Ontario | Canada | 44.63 | -80.95 | 830 | 11755 |
| Sarnia | city | Ontario | Canada | 42.98 | -82.39 | 830 | 49278 |
| Sault Sainte Marie | city | Ontario | Canada | 46.50 | -84.33 | 830 | 29830 |
| Sault Ste. Marie | city | Ontario | Canada | 46.50 | -84.33 | 830 | 29830 |
| Sault-Sainte-Marie | city | Ontario | Canada | 46.50 | -84.33 | 830 | 29830 |
| Savanne | city | Ontario | Canada | 48.95 | -90.25 | 1669 | 0 |
| Savant Lake | city | Ontario | Canada | 50.23 | -90.72 | 1669 | 170 |
| Scarborough | city | Ontario | Canada | 43.75 | -79.20 | 410 | 190629 |
| Scarborough | city | Ontario | Canada | 43.78 | -79.25 | 830 | 292740 |
| Scarborough Junction | city | Ontario | Canada | 43.72 | -79.25 | 830 | 201873 |
| Scarborough Township | city | Ontario | Canada | 43.78 | -79.25 | 830 | 292740 |
| Schomberg | city | Ontario | Canada | 44.01 | -79.68 | 830 | 3340 |
| Schreiber | city | Ontario | Canada | 48.80 | -87.27 | 1040 | 2573 |
| Schumacher | city | Ontario | Canada | 48.47 | -81.28 | 1108 | 6108 |
| Scotia | city | Ontario | Canada | 45.52 | -79.30 | 1092 | 1033 |
| Scotland | city | Ontario | Canada | 43.03 | -80.37 | 830 | 2303 |
| Scotty Springs | city | Ontario | Canada | 48.37 | -80.25 | 1003 | 133 |
| Scudder | city | Ontario | Canada | 41.82 | -82.65 | 830 | 223 |
| Seaforth | city | Ontario | Canada | 43.55 | -81.40 | 1023 | 4788 |
| Seagrave | city | Ontario | Canada | 44.20 | -78.95 | 892 | 2606 |
| Searchmont | city | Ontario | Canada | 46.78 | -84.05 | 830 | 0 |
| Sebringville | city | Ontario | Canada | 43.41 | -81.06 | 1164 | 2699 |
| Seeley Bay | city | Ontario | Canada | 44.48 | -76.23 | 321 | 756 |
| Selby | city | Ontario | Canada | 44.30 | -76.98 | 377 | 4843 |
| Selkirk | city | Ontario | Canada | 42.83 | -79.93 | 830 | 611 |
| Sellwood | city | Ontario | Canada | 46.85 | -81.02 | 1230 | 380 |
| Sent Katerinsas | city | Ontario | Canada | 43.17 | -79.23 | 337 | 99048 |
| Severn | city | Ontario | Canada | 55.98 | -87.65 | 3 | 208 |
| Severn | city | Ontario | Canada | 44.77 | -79.33 | 830 | 5206 |
| Severn Bridge | city | Ontario | Canada | 44.77 | -79.33 | 830 | 5206 |
| Shabagua | city | Ontario | Canada | 48.58 | -89.90 | 1669 | 0 |
| Shabaqua | city | Ontario | Canada | 48.58 | -89.90 | 1669 | 0 |
| Shakespeare | city | Ontario | Canada | 43.37 | -80.84 | 1243 | 1926 |
| Shannonville | city | Ontario | Canada | 44.19 | -77.23 | 262 | 2493 |
| Sharbet Lake | city | Ontario | Canada | 44.78 | -76.68 | 830 | 637 |
| Sharbot Lake | city | Ontario | Canada | 44.78 | -76.68 | 830 | 637 |
| Shawanaga | city | Ontario | Canada | 45.52 | -80.28 | 830 | 77 |
| Shebandowan | city | Ontario | Canada | 48.63 | -90.07 | 1669 | 0 |
| Shedden | city | Ontario | Canada | 42.74 | -81.35 | 830 | 0 |
| Sheffield | city | Ontario | Canada | 43.33 | -80.21 | 839 | 1231 |
| Shelburne | city | Ontario | Canada | 44.08 | -80.20 | 1669 | 8181 |
| Sherkston | city | Ontario | Canada | 42.89 | -79.13 | 830 | 10779 |
| Sheshegwaning | city | Ontario | Canada | 45.90 | -82.83 | 830 | 4 |
| Shillington | city | Ontario | Canada | 48.53 | -80.68 | 872 | 149 |
| Shirleys Bay | city | Ontario | Canada | 45.37 | -75.88 | 200 | 40123 |
| Silver Islet | city | Ontario | Canada | 48.33 | -88.82 | 830 | 0 |
| Silver Mountain | city | Ontario | Canada | 48.25 | -89.88 | 1669 | 0 |
| Simcoe | city | Ontario | Canada | 42.84 | -80.31 | 830 | 21913 |
| Sioux Lookout | city | Ontario | Canada | 50.10 | -91.92 | 1217 | 4570 |
| Skead | city | Ontario | Canada | 46.67 | -80.75 | 980 | 1756 |
| Sleeman | city | Ontario | Canada | 48.69 | -94.44 | 1072 | 188 |
| Smiths Falls | city | Ontario | Canada | 44.90 | -76.02 | 380 | 16105 |
| Smithville | city | Ontario | Canada | 43.10 | -79.55 | 830 | 15218 |
| Smooth Rock Falls | city | Ontario | Canada | 49.28 | -81.63 | 830 | 602 |
| Sombra | city | Ontario | Canada | 42.71 | -82.47 | 830 | 10853 |
| South Augusta | city | Ontario | Canada | 44.65 | -75.65 | 347 | 8905 |
| South Baymouth | city | Ontario | Canada | 45.55 | -82.02 | 830 | 120 |
| South Buxton | city | Ontario | Canada | 42.28 | -82.18 | 830 | 0 |
| South Easthope | city | Ontario | Canada | 43.33 | -80.92 | 1177 | 6427 |
| South Lancaster | city | Ontario | Canada | 45.13 | -74.48 | 144 | 1117 |
| South March | city | Ontario | Canada | 45.35 | -75.93 | 282 | 35440 |
| South Mountain | city | Ontario | Canada | 44.99 | -75.45 | 249 | 902 |
| South Porcupine | city | Ontario | Canada | 48.47 | -81.20 | 1072 | 5622 |
| South River | city | Ontario | Canada | 45.85 | -79.37 | 1112 | 1609 |
| South Woodslee | city | Ontario | Canada | 42.20 | -82.72 | 830 | 961 |
| Southampton | city | Ontario | Canada | 44.50 | -81.37 | 830 | 4837 |
| Spanish | city | Ontario | Canada | 46.18 | -82.33 | 830 | 233 |
| Sparta | city | Ontario | Canada | 42.70 | -81.08 | 830 | 129 |
| Spencerville | city | Ontario | Canada | 44.84 | -75.54 | 298 | 0 |
| Spragge | city | Ontario | Canada | 46.20 | -82.67 | 830 | 153 |
| Springfield | city | Ontario | Canada | 42.83 | -80.93 | 830 | 2919 |
| Sproule | city | Ontario | Canada | 45.62 | -78.40 | 1669 | 0 |
| Sproule Township | city | Ontario | Canada | 45.62 | -78.40 | 1669 | 0 |
| Sprucedale | city | Ontario | Canada | 45.48 | -79.47 | 1135 | 298 |
| St. Catharines | city | Ontario | Canada | 43.17 | -79.23 | 337 | 99048 |
| St. Marys | city | Ontario | Canada | 43.25 | -81.13 | 1026 | 8933 |
| St. Thomas | city | Ontario | Canada | 42.78 | -81.19 | 830 | 37453 |
| Staffa | city | Ontario | Canada | 43.44 | -81.34 | 1062 | 596 |
| Stamford | city | Ontario | Canada | 43.13 | -79.10 | 830 | 36338 |
| Staples | city | Ontario | Canada | 42.17 | -82.59 | 830 | 761 |
| Stayner | city | Ontario | Canada | 44.42 | -80.08 | 830 | 6745 |
| Steep Rock Lake | city | Ontario | Canada | 48.83 | -91.67 | 1669 | 424 |
| Stella | city | Ontario | Canada | 44.17 | -76.69 | 272 | 1654 |
| Stevensville | city | Ontario | Canada | 42.94 | -79.06 | 830 | 20222 |
| Stirling | city | Ontario | Canada | 44.30 | -77.55 | 400 | 6565 |
| Stittsville | city | Ontario | Canada | 45.26 | -75.92 | 390 | 19967 |
| Stonecliffe | city | Ontario | Canada | 46.22 | -77.88 | 830 | 0 |
| Stoney Creek | city | Ontario | Canada | 43.22 | -79.75 | 830 | 95709 |
| Stoney Point | city | Ontario | Canada | 42.31 | -82.55 | 830 | 1593 |
| Stony | city | Ontario | Canada | 43.22 | -79.75 | 830 | 95709 |
| Stouffville | city | Ontario | Canada | 43.97 | -79.25 | 846 | 39177 |
| Stouffville Junction | city | Ontario | Canada | 43.97 | -79.25 | 846 | 39177 |
| Straffordville | city | Ontario | Canada | 42.75 | -80.78 | 830 | 1356 |
| Stratford | city | Ontario | Canada | 43.37 | -80.98 | 1177 | 35064 |
| Strathburn | city | Ontario | Canada | 42.72 | -81.67 | 830 | 4071 |
| Strathroy | city | Ontario | Canada | 42.96 | -81.62 | 830 | 17103 |
| Stratton | city | Ontario | Canada | 48.66 | -94.17 | 1092 | 82 |
| Streetsville | city | Ontario | Canada | 43.58 | -79.72 | 830 | 189425 |
| Strickland | city | Ontario | Canada | 49.28 | -81.85 | 830 | 41 |
| Sturgeon Falls | city | Ontario | Canada | 46.37 | -79.93 | 830 | 8623 |
| Sudbury | city | Ontario | Canada | 46.50 | -80.97 | 898 | 25707 |
| Sulphide | city | Ontario | Canada | 44.52 | -77.22 | 830 | 686 |
| Sultan | city | Ontario | Canada | 47.58 | -82.77 | 1669 | 0 |
| Summerstown | city | Ontario | Canada | 45.07 | -74.56 | 173 | 188 |
| Sundridge | city | Ontario | Canada | 45.77 | -79.40 | 1082 | 1819 |
| Sutton | city | Ontario | Canada | 44.30 | -79.37 | 830 | 9402 |
| Sutton West | city | Ontario | Canada | 44.30 | -79.37 | 830 | 9402 |
| Swain Post | city | Ontario | Canada | 51.27 | -92.68 | 1669 | 0 |
| Swansea | city | Ontario | Canada | 43.63 | -79.47 | 246 | 302452 |
| Swastika | city | Ontario | Canada | 48.10 | -80.10 | 980 | 2266 |
| Sydenham | city | Ontario | Canada | 44.57 | -80.80 | 1108 | 1313 |
| Sydenham | city | Ontario | Canada | 44.41 | -76.60 | 830 | 1890 |
| Sylvan | city | Ontario | Canada | 43.15 | -81.78 | 830 | 544 |