| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Siderka | city | Poland | 53.60 | 23.47 | 551 | 2238 | |
| Sidra | city | Poland | 53.57 | 23.45 | 515 | 2138 | |
| Siedlece | city | Poland | 52.63 | 22.92 | 531 | 1978 | |
| Siekierka | city | Poland | 53.55 | 23.42 | 547 | 2237 | |
| Siekierki | city | Poland | 52.52 | 22.62 | 479 | 2608 | |
| Siekierki | city | Poland | 53.18 | 22.87 | 472 | 3433 | |
| Siekluki | city | Poland | 52.63 | 22.97 | 511 | 1827 | |
| Sielachowskie | city | Poland | 53.20 | 23.15 | 459 | 51234 | |
| Sielc | city | Poland | 52.65 | 22.92 | 518 | 2049 | |
| Siemianowka | city | Poland | 52.90 | 23.83 | 482 | 1212 | |
| Siemiatycze | city | Poland | 52.45 | 22.88 | 570 | 13615 | |
| Siemichocze | city | Poland | 52.43 | 23.20 | 580 | 1686 | |
| Siemieniówka | city | Poland | 52.90 | 23.83 | 482 | 1212 | |
| Siemiony | city | Poland | 52.62 | 22.78 | 521 | 1963 | |
| Siemionówka | city | Poland | 52.90 | 23.83 | 482 | 1212 | |
| Sieniewice | city | Poland | 52.43 | 22.67 | 577 | 2796 | |
| Sieniewicze | city | Poland | 52.43 | 22.67 | 577 | 2796 | |
| Sienkiewicze | city | Poland | 53.13 | 23.05 | 495 | 63287 | |
| Sierakowizna | city | Poland | 52.75 | 23.00 | 538 | 935 | |
| Sierakowizny | city | Poland | 52.75 | 23.00 | 538 | 935 | |
| Sierbowce | city | Poland | 53.45 | 23.45 | 541 | 5257 | |
| Sierbowice | city | Poland | 53.45 | 23.45 | 541 | 5257 | |
| Sierki | city | Poland | 53.18 | 22.73 | 508 | 2532 | |
| Sieski | city | Poland | 52.98 | 23.37 | 498 | 228 | |
| Sieski | city | Poland | 52.85 | 22.82 | 505 | 2493 | |
| Sikory | city | Poland | 53.40 | 22.88 | 511 | 6105 | |
| Sikory Bartkowięta | city | Poland | 53.15 | 22.63 | 446 | 2212 | |
| Simuny | city | Poland | 52.97 | 23.10 | 498 | 4061 | |
| Sitawka | city | Poland | 53.45 | 23.25 | 570 | 1788 | |
| Sitkowo | city | Poland | 53.40 | 23.20 | 679 | 2567 |