| Etters observatory | Estados Unidos | Pensilvania | — |
| Etyek observatory | Hungría | Etyek | — |
 Euclid | — | — | — |
| Eulji Observatory | Corea del Sur | Haean-myeon | — |
| Eurac observatory | Italia | Bolzano | — |
 EURECA | — | — | — |
| Eureka Magnetic Observatory | Canadá | Nunavut | — |
| European Gravitational Observatory | Italia | Cascina | — |
| European Southern Observatory | Chile | Ipomoea arborescens | — |
| European Southern Observatory, La Silla-DSS | Chile | Ipomoea arborescens | — |
| Europlanetarium Genk | Bélgica | — | — |
| Evelyn L. Egan Observatory | Estados Unidos | Estero | — |
| Everstar Observatory | Estados Unidos | Olathe | — |
 Evpatoria Observatory | Rusia | Molochno Village Council | — |
| Ex Nihilo Observatory | Estados Unidos | Statham | — |
 Exosat | — | — | — |
| Experimenta observatory | Alemania | Heilbronn | — |
| Experimental Test Site | Estados Unidos | New Mexico | — |
 Experimento de Neutrinos de la Bahía de Daya | República Popular China | — | — |
 Experimento de Neutrinos Subterráneo Profundo | Estados Unidos | Municipio de Winfield | — |
| Experimento del neutrino | — | — | — |
| EXPO-Sternwarte Melle | Alemania | Melle | — |
 Extreme Ultraviolet Explorer | — | — | — |
| Eygalayes observatory | Francia | Eygalayes | — |
| Eyrewell Magnetic Observatory | Nueva Zelanda | — | — |
| F.Schiller-Gymnasium, observatory | Alemania | Weimar | — |
 Fabra observatory | España | Ager | — |
 Fair Isle Bird Observatory | Reino Unido | Islas Shetland | — |
| Fair Oaks Ranch observatory | Estados Unidos | Texas | — |
| Falkensee observatory | Alemania | Falkensee | — |
| Fan Mountain Observatory | Estados Unidos | Virginia | — |
 Far Ultraviolet Spectroscopic Explorer | Estados Unidos | — | — |
 Farm Cove Observatory | Nueva Zelanda | Auckland Region | — |
| Fayetteville observatory | Estados Unidos | Fayetteville | — |
 Federal Observatory | Suiza | Zúrich | — |
| Felliscopio Observatory | Italia | Fellicarolo | — |
| Felsina AAB observatory | Italia | Monte San Pietro | — |
| Fenton Hill Observatory | Estados Unidos | New Mexico | — |
| Fenwick Observatory | Estados Unidos | Woodside | — |
 Ferdinando Caliumi astronomic observatory | Italia | Gairo | 1.150 m |
 Fernbank Observatory | Estados Unidos | Georgia | — |
| Fiamene observatory | Italia | Verona | — |
| Fiby observatory | Suecia | Upsala | — |
| Fick Observatory | Estados Unidos | Iowa | — |
| Filey Bird Observatory | Reino Unido | Filey | — |
| Filzi School observatory | Italia | Laives | — |
| Fiore Observatory | Italia | Precenicco | — |
| Fire in the Sky Observatory | Estados Unidos | Brainerd | — |