 Hartebeesthoek Radio Astronomy Observatory | Sudáfrica | Krugersdorp | — |
| Hartland Magnetic Observatory | Reino Unido | — | — |
| Hartley Wintney observatory | Reino Unido | Hartley Wintney | — |
 Hartung–Boothroyd Observatory | Estados Unidos | Nueva York | — |
| Hartwell observatory | Reino Unido | Hartwell | — |
 Harvard-Smithsonian Center for Astrophysics | Estados Unidos | Cambridge | — |
| Harvest Moon observatory | Estados Unidos | Terre Haute | — |
| Harvest observatory | Estados Unidos | Harvest | — |
 Hat Creek Radio Observatory | Estados Unidos | California | — |
| Hatamae observatory | Japón | Sendai | — |
 Haterumajima Astronomical Observatory Tower | Japón | Taketomi | — |
| Haute Provence Sud Observatory | Francia | Saint-Michel-l'Observatoire | — |
| Haverford observatory | Estados Unidos | Municipio de Haverford | — |
| Haverhill observatory | Reino Unido | Haverhill | — |
| Hawaii Center for Volcanology | Estados Unidos | — | — |
| Hawker observatory | Australia | Hawker | — |
| Hawkeye Observatory | Estados Unidos | Durand | — |
 Haynald Observatory | Hungría | Kalocsa | — |
| Hazardous Observatory | Estados Unidos | Mayhill | — |
| Hazelbrook observatory | Australia | Hazelbrook | — |
 HDST | — | — | — |
| Heartland Observatory | Estados Unidos | Carmel | — |
| Heaven on Earth Observatory | Estados Unidos | Weed Lookout Tower | — |
| Heaven's Mirror Observatory | Australia | Manton | — |
| Heavenly Owl observatory | Ucrania | Velikodolinske | — |
| Hector J. Robinson Observatory | Estados Unidos | Condado de Wayne | — |
 Heinz-Reinhardt-Sternwarte St. Ottilien | Alemania | — | — |
| Heisingen Observatory | Alemania | Essen | — |
 Hel Magnetic Observatory | Polonia | Hel | — |
 Heligoland Bird Observatory | Alemania | Heligoland | — |
 Heliometer building, Old Observatory, Leiden | Países Bajos | Leiden | — |
| Helios Ontigola observatory | España | Ontígola | — |
| Heliotropion | — | — | — |
| Helium and Lead Observatory | Canadá | — | — |
 Hellendoorn Public Observatory | Países Bajos | Hellendoorn | — |
| Helmut Ullrich Astronomical Observatory | Italia | Cortina d’Ampezzo | — |
| Hemedan observatory | — | — | — |
| Hemet observatory | Estados Unidos | Hemet | — |
| Hemingford Abbots observatory | Reino Unido | Hemingford Abbots | — |
| Hennef observatory | Alemania | Hennef | — |
 Hereford Arizona Observatory | Estados Unidos | Arizona | 1.423 m |
| Hermanus Magnetic Observatory | Sudáfrica | — | — |
| Heron Cove Observatory | Estados Unidos | Orcas Village | — |
| Herrenberg Observatory | Alemania | Herrenberg | — |
| Herrett Observatory | Estados Unidos | Idaho | — |
| Herrsching observatory | Alemania | Herrsching am Ammersee | — |
 Herschel | — | — | — |
 Herstmonceux Science Centre | Reino Unido | Herstmonceux | — |