| Starlab Observatory | Rusia | Nizhny Arkhyz | — |
| Starlight Observatory | República Popular China | Condado de Anji | — |
| Starry Knight observatory | Estados Unidos | California | — |
| Starry Night Observatory | Estados Unidos | Glidden | — |
| Starry Wanderer observatory | Bielorrusia | Baran | — |
| STARS-AO | Japón | — | — |
 Stará hvězdárna | República Checa | Valašské Meziříčí | — |
| Stazione Astronomica Betelgeuse observatory | Italia | Magnago | — |
| Stazione Astronomica Le Pleiadi | Italia | Taverna | — |
 Stellafane | Estados Unidos | Springfield | — |
| Stellarium Gornergrat | Suiza | Zermatt | — |
| Stennis Space Center Magnetic Observatory | Estados Unidos | — | — |
| Stephanion Observatory | Grecia | — | — |
| Stephens Observatory | Estados Unidos | Maine | — |
 STEREO-A | — | — | — |
| STEREO-B | — | — | — |
 Sterngarten | Austria | Mauer | 329 m |
| Sterni Observatory | Alemania | Kempten | — |
 Sternwarte Aachen | Alemania | Aachen-Mitte | 204 m |
 Sternwarte Bülach | Suiza | Bülach | — |
| Sternwarte Calden | Alemania | Calden | — |
 Sternwarte Davidschlag | Austria | Kirchschlag bei Linz | 815 m |
| Sternwarte Feuerstein | Alemania | Ebermannstadt | 500 m |
| Sternwarte Greifswald | Alemania | Greifswald | 9 m |
 Sternwarte Herne | Alemania | Herne | 52 m |
 Sternwarte Hof | Alemania | Hof | — |
| Sternwarte Kassel | Alemania | Kassel | — |
 Sternwarte Kirchheim | Alemania | Amt Wachsenburg | 267 m |
| Sternwarte Limburg | Alemania | Limburgo del Lahn | — |
| Sternwarte Metzerlen | Suiza | Soleura | — |
 Sternwarte Mirasteilas | Suiza | Falera | — |
 Sternwarte Neanderhöhe Hochdahl | Alemania | Erkrath | 137 m |
| Sternwarte Neuenhaus | Alemania | Neuenhaus | 18 m |
 Sternwarte Rümlang | Suiza | Rümlang | — |
 Sternwarte Simplon-Adler | Suiza | Simplon | — |
| Sternwarte Sirius | Suiza | Sigriswil | — |
| Sternwarte Tentlingen | Suiza | Tentlingen | — |
 Sternwarte Tübingen | Alemania | Tubinga | 470 m |
 Sternwarte und Planetarium „Sigmund Jähn“ Rodewisch | Alemania | Rodewisch | — |
 Sternwarte Weikersheim | Alemania | Weikersheim | 332 m |
 Sternwarte Welzheim | Alemania | Welzheim | 547 m |
| Sternwarte Wetzikon | Suiza | Wetzikon | — |
 Sternwarten des ehemaligen Forschungsinstituts Manfred von Ardenne | Alemania | Dresde | — |
| Sterrenwacht Andromeda observatory | Países Bajos | Ellecom | — |
| Sterrenwacht Gooi en Vechtstreek | Países Bajos | — | — |
 Sterrenwacht Limburg | Países Bajos | Heerlen | — |
| Sterrenwacht Rijswijk | Países Bajos | Rijswijk | — |
| Stia observatory | Italia | Stia | — |