| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sage Junction | city | Idaho | United States | 43.83 | -112.20 | 5029 | |
| Sagle | city | Idaho | United States | 48.20 | -116.55 | 2509 | |
| Saint Anthony | city | Idaho | United States | 43.97 | -111.68 | 5029 | |
| Saint Charles | city | Idaho | United States | 42.11 | -111.39 | 5957 | |
| Saint Joe | city | Idaho | United States | 47.31 | -116.35 | 2509 | |
| Saint Johns | city | Idaho | United States | 42.21 | -112.29 | 4599 | |
| Saint Maries | city | Idaho | United States | 47.31 | -116.56 | 2509 | |
| Salem | city | Idaho | United States | 43.88 | -111.77 | 5029 | |
| Salmon | city | Idaho | United States | 45.18 | -113.90 | 4189 | |
| Salubria | city | Idaho | United States | 44.56 | -116.67 | 2700 | |
| Sam | city | Idaho | United States | 43.72 | -111.30 | 6768 | |
| Samaria | city | Idaho | United States | 42.12 | -112.34 | 4442 | |
| Sampson | city | Idaho | United States | 45.52 | -116.01 | 5997 | |
| Samuels | city | Idaho | United States | 48.43 | -116.49 | 2509 | |
| Sand Hollow | city | Idaho | United States | 43.81 | -116.75 | 2509 | |
| Sanders | city | Idaho | United States | 47.11 | -116.80 | 2700 | |
| Sandpoint | city | Idaho | United States | 48.28 | -116.55 | 2060 | |
| Sands (historical) | city | Idaho | United States | 43.49 | -116.91 | 2598 | |
| Santa | city | Idaho | United States | 47.15 | -116.45 | 2798 | |
| Sarilda | city | Idaho | United States | 44.11 | -111.57 | 5311 | |
| Sawtooth City (historical) | city | Idaho | United States | 43.90 | -114.84 | 7549 | |
| Sawyer | city | Idaho | United States | 48.14 | -116.76 | 2509 | |
| Schiller | city | Idaho | United States | 42.88 | -112.66 | 4406 | |
| Schnoors | city | Idaho | United States | 48.69 | -116.34 | 1791 | |
| Schodde | city | Idaho | United States | 42.61 | -113.99 | 4189 | |
| Schow | city | Idaho | United States | 42.59 | -113.71 | 4189 | |
| Scoville | city | Idaho | United States | 43.48 | -113.00 | 5029 | |
| Seaburg | city | Idaho | United States | 45.48 | -116.03 | 6030 | |
| Sebree | city | Idaho | United States | 43.19 | -115.79 | 3349 | |
| Selby | city | Idaho | United States | 43.34 | -114.71 | 5029 | |
| Selle | city | Idaho | United States | 48.36 | -116.49 | 2509 | |
| Seneacquoteen | city | Idaho | United States | 48.15 | -116.76 | 2509 | |
| Setters | city | Idaho | United States | 47.47 | -117.01 | 2585 | |
| Sharon | city | Idaho | United States | 42.35 | -111.48 | 6207 | |
| Shelley | city | Idaho | United States | 43.38 | -112.12 | 5029 | |
| Shells Lick | city | Idaho | United States | 45.71 | -116.13 | 5869 | |
| Sherwin | city | Idaho | United States | 46.95 | -116.35 | 3349 | |
| Sherwood Beach | city | Idaho | United States | 48.50 | -116.84 | 2509 | |
| Shiloh | city | Idaho | United States | 48.54 | -116.40 | 3349 | |
| Shoreline Drive Summer Home Area | city | Idaho | United States | 44.65 | -115.68 | 5298 | |
| Shoshone | city | Idaho | United States | 42.94 | -114.41 | 4189 | |
| Shoup | city | Idaho | United States | 45.38 | -114.28 | 4402 | |
| Silver Beach | city | Idaho | United States | 47.95 | -116.89 | 2509 | |
| Silver City | city | Idaho | United States | 43.02 | -116.73 | 6709 | |
| Silver Sands Beach | city | Idaho | United States | 47.89 | -116.88 | 2509 | |
| Silver Star | city | Idaho | United States | 42.08 | -111.95 | 4603 | |
| Silvertip Landing | city | Idaho | United States | 47.36 | -116.69 | 2509 | |
| Silverton | city | Idaho | United States | 47.49 | -115.96 | 2801 | |
| Simplot | city | Idaho | United States | 43.67 | -116.73 | 2509 | |
| Sinclair | city | Idaho | United States | 48.93 | -116.18 | 3349 | |
| Sinker (historical) | city | Idaho | United States | 43.12 | -116.51 | 3398 | |
| Slabtown | city | Idaho | United States | 46.87 | -116.39 | 3349 | |
| Slacks Corner | city | Idaho | United States | 43.08 | -116.74 | 6738 | |
| Slate Creek | city | Idaho | United States | 45.64 | -116.28 | 1735 | |
| Slickpoo | city | Idaho | United States | 46.32 | -116.71 | 2509 | |
| Slocum | city | Idaho | United States | 46.56 | -116.02 | 3349 | |
| Smaq'wqn Hill | city | Idaho | United States | 47.48 | -116.60 | 2509 | |
| Smelter Heights | city | Idaho | United States | 47.54 | -116.16 | 2509 | |
| Smelterville | city | Idaho | United States | 47.54 | -116.18 | 2509 | |
| Smith Corrals | city | Idaho | United States | 43.33 | -113.25 | 5200 | |
| Smith Springs | city | Idaho | United States | 42.64 | -113.31 | 4189 | |
| Smiths Ferry | city | Idaho | United States | 44.30 | -116.09 | 5029 | |
| Snow (historical) | city | Idaho | United States | 46.30 | -116.79 | 2509 | |
| Soda Springs | city | Idaho | United States | 42.65 | -111.60 | 5869 | |
| Soldier | city | Idaho | United States | 43.37 | -114.79 | 5088 | |
| Sonna | city | Idaho | United States | 43.61 | -116.46 | 2582 | |
| South Boise (historical) | city | Idaho | United States | 43.58 | -116.17 | 2798 | |
| South Mountain | city | Idaho | United States | 42.75 | -116.92 | 6876 | |
| Southwick | city | Idaho | United States | 46.60 | -116.47 | 2900 | |
| Spalding | city | Idaho | United States | 46.45 | -116.82 | 889 | |
| Spanish Town (historical) | city | Idaho | United States | 43.71 | -115.26 | 5902 | |
| Spencer | city | Idaho | United States | 44.36 | -112.19 | 5869 | |
| Spink | city | Idaho | United States | 44.79 | -116.05 | 5029 | |
| Spirit Lake | city | Idaho | United States | 47.97 | -116.87 | 2611 | |
| Spiry Place | city | Idaho | United States | 42.91 | -116.41 | 3398 | |
| Springdale | city | Idaho | United States | 42.52 | -113.69 | 4189 | |
| Springfield | city | Idaho | United States | 43.08 | -112.68 | 4399 | |
| Springston | city | Idaho | United States | 47.48 | -116.73 | 2736 | |
| Squirrel | city | Idaho | United States | 44.03 | -111.30 | 5869 | |
| Staley Springs | city | Idaho | United States | 44.66 | -111.44 | 6709 | |
| Stanford | city | Idaho | United States | 46.83 | -116.64 | 2798 | |
| Stanley | city | Idaho | United States | 44.22 | -114.94 | 6709 | |
| Stanton Crossing | city | Idaho | United States | 43.33 | -114.31 | 5029 | |
| Star | city | Idaho | United States | 43.69 | -116.49 | 2509 | |
| Star Ranch Summer Home Area | city | Idaho | United States | 43.91 | -115.97 | 4202 | |
| Starkey | city | Idaho | United States | 44.85 | -116.45 | 3349 | |
| State Line Village | city | Idaho | United States | 47.70 | -117.04 | 2509 | |
| Steamboat (historical) | city | Idaho | United States | 47.68 | -116.14 | 2598 | |
| Steamboat Rock | city | Idaho | United States | 43.45 | -115.63 | 4189 | |
| Steamboat Rocks | city | Idaho | United States | 47.91 | -116.13 | 3349 | |
| Sterling | city | Idaho | United States | 43.04 | -112.73 | 4360 | |
| Stetson | city | Idaho | United States | 47.28 | -115.77 | 2598 | |
| Stevens | city | Idaho | United States | 44.85 | -116.38 | 3599 | |
| Stibnite | city | Idaho | United States | 44.90 | -115.34 | 6709 | |
| Stites | city | Idaho | United States | 46.09 | -115.98 | 1669 | |
| Stone | city | Idaho | United States | 42.02 | -112.70 | 4498 | |
| Stout Crossing | city | Idaho | United States | 43.15 | -115.31 | 5029 | |
| Strevell | city | Idaho | United States | 42.01 | -113.20 | 5305 | |
| Striker | city | Idaho | United States | 42.47 | -114.31 | 4189 | |
| Stull | city | Idaho | United States | 47.47 | -115.86 | 3349 | |
| Sturgeon | city | Idaho | United States | 47.85 | -116.86 | 2509 | |
| Sublett | city | Idaho | United States | 42.31 | -113.14 | 5029 | |
| Sugar City | city | Idaho | United States | 43.87 | -111.75 | 5029 | |
| Sugar Loaf | city | Idaho | United States | 42.68 | -114.38 | 4189 | |
| Sun Valley | city | Idaho | United States | 43.70 | -114.35 | 5997 | |
| Sunbeam | city | Idaho | United States | 44.27 | -114.73 | 6082 | |
| Sunbeam Post Office (historical) | city | Idaho | United States | 44.27 | -114.73 | 6082 | |
| Sunnydell | city | Idaho | United States | 43.68 | -111.75 | 5029 | |
| Sunnyside | city | Idaho | United States | 48.28 | -116.40 | 2060 | |
| Sunnyslope | city | Idaho | United States | 43.59 | -116.79 | 2509 | |
| Sunset (historical) | city | Idaho | United States | 47.56 | -115.84 | 5869 | |
| Swan Falls | city | Idaho | United States | 43.24 | -116.37 | 2509 | |
| Swan Lake | city | Idaho | United States | 42.31 | -112.00 | 5029 | |
| Swan Valley | city | Idaho | United States | 43.46 | -111.34 | 5869 | |
| Swanlake | city | Idaho | United States | 42.31 | -112.00 | 5029 | |
| Swartz Corner | city | Idaho | United States | 43.50 | -116.56 | 2614 | |
| Sweeney | city | Idaho | United States | 47.54 | -116.17 | 2509 | |
| Sweet | city | Idaho | United States | 43.97 | -116.32 | 2598 | |
| Sweet Sage (historical) | city | Idaho | United States | 43.83 | -112.93 | 5029 | |
| Sweetwater | city | Idaho | United States | 46.37 | -116.79 | 1669 | |
| Syringa | city | Idaho | United States | 46.15 | -115.73 | 1669 |