Si
- Sidney, Vancouver Island, British Columbia, Canada
- Sieburg, Westphalia, Germany
- Siem Reab, Cambodia
- Siena, Emilia-Romagna, Italy
- Siena, Tuscany, Italy
- Sierra Leone
- Sierra Vista, Arizona, USA
- Sigatoka, Fiji
- Siguirusua River, Colombia
- Sikaiana, Solomon Islands
- Silesia, Germany
- Siletz, Oregon, USA
- Siletz Indian Reservation, Lincoln County, Oregon, USA
- Siletz River, Oregon, USA
- Silifke, Mersin, Turkey
- Sillustani, Puno, Peru
- Similkameen, Canada
- Similkameen, Washington, USA
- Simpson Bay, Canada
- Simutak, Greenland
- Sinclair Lake, British Columbia, Canada
- Sindh, Pakistan
- Singapore
- Sinkut Creek, British Columbia, Canada
- Sinta Ka Heen Ee, Juneau Borough, Alaska, USA
- Sinta Ka Heenee, Juneau Borough, Alaska, USA
- Sinta-ka-heen-ee, Admiralty Island, Alaska, USA
- Sintra, Lisboa, Portugal
- Siorapaluk, Greenland
- Sirorata, Oro, Papua New Guinea
- Sisak, Croatia
- Sisimiut, Greenland
- Sitka, Alaska, USA
- Sitka, Baranof Island, Alaska, USA
- Sitka, Baranof Island, Sitka Borough, Alaska, USA
- Sitka, Nakwasina Bay, Baranof Island, Sitka Borough, Alaska, USA
- Sitka, Sitka Division, Alaska, USA
- Sitka Bay, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Borough, Alaska, USA
- Sitka Division, Alaska, USA
- Sitka Harbor, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Harbor, Japonski Island, Sitka Borough, Alaska, USA
- Sitka Qwan, 12 Miles South Of Sitka, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Qwan, 30 Miles North Of Sitka, Peril Strait, Sitka Borough, Alaska, USA
- Sitka Qwan, Hallock Island, Alaska, USA
- Sitka Qwan, Japonski Island, Sitka Borough, Alaska, USA
- Sitka Qwan, Opposite Sitka, Japonski Island, Sitka Borough, Alaska, USA
- Sitka Qwan, Peril Strait, Sitka Borough, Alaska, USA
- Sitka Qwan, Sitka, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Qwan, Sitka Bay, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Qwan, Sitka Borough, Alaska, USA
- Sitka Qwan, Sitka, Nakwasina Bay, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Qwan, Sitka Vicinity, Baranof Island, Sitka Borough, Alaska, USA
- Sitka Vicinity, Baranof Island, Sitka Borough, Alaska, USA
- Sivakasi, Tamil Nadu, India
- Siwash Creek, British Columbia, Canada
Sk
- Skagit County, Washington, USA
- Skagway, Alaska, Angoon, Alaska, USA
- Skagway, Alaska, USA
- Skagway-Hoonah-Angoon Division, Alaska, USA
- Skatin, British Columbia, Canada
- Skaukail, Chilliwack, British Columbia, Canada
- Skedans, British Columbia, Canada
- Skedans, Haida Gwaii, British Columbia, Canada
- Skeena And Nais River, British Columbia, Canada
- Skeena Crossing, British Columbia, Canada
- Skeena River, British Columbia, Canada
- Skeena-Queen Charlotte A, British Columbia, Canada
- Skidegate, British Columbia, Canada
- Skidegate, Graham Island, Haida Gwaii, British Columbia, Canada
- Skidegate, Haida Gwaii, British Columbia, Canada
- Skidegate Inlet, Haida Gwaii, British Columbia, Canada
- Skins Lake, British Columbia, Canada
- Skookumchuck, British Columbia, Canada
- Skopje, Serbia
- Skunggwai, British Columbia, Canada
SlSm
- Smith Inlet, British Columbia, Canada
- Smith Inlet, Queen Charlotte Sound, British Columbia, Canada
- Smith River, California, USA
- Smith Sound, Greenland
- Smith Sound, Kokan, Greenland
- Smith Sound, North Greenland, Greenland
- Smithers, British Columbia, Canada
SnSo
- Sobotiste, Slovakia
- Soda Creek, British Columbia, Canada
- Sogeri, Papua New Guinea
- Soji-Mura, Tottori, Japan
- Solala, Guatemala
- Solola, Guatemala
- Solola, Solola, Guatemala
- Solomon Islands
- Somalia
- Somenos Creek, British Columbia, Canada
- Somme, France
- Somme Valley, France