| Haagaar Observatory | Noruega | Eina | — |
| Hablainville observatory | Francia | Hablainville | — |
| Hagen Observatory | Alemania | Finnentrop | — |
| Hagerstown observatory | Estados Unidos | Hagerstown | — |
 Haggart Observatory | Estados Unidos | Oregón | — |
| Hainan Island station | República Popular China | Xuanwu | — |
 Hakin Observatory | Reino Unido | Milford Haven | 49,4 m |
| Hakos Observatory | Namibia | Khomas Region | 1.852 m |
 Haldde observatory | Noruega | Alta | — |
| Hale Observatories | — | — | — |
 Hale Solar Laboratory | Estados Unidos | California | — |
| Haleakala-LCO Clamshell #3 | Estados Unidos | Kula | — |
| Haleakala-LCO OGG B #2 | Estados Unidos | Kula | — |
| Hallet Cove observatory | Australia | Hallett Cove | — |
 Halley observatory | Países Bajos | Bernheze | — |
| Halstead Observatory | Estados Unidos | Princeton | — |
 Hamamatsu City Observatory | Japón | Minami-ku | — |
| Hamamatsu-Yuto observatory | Japón | Hamamatsu | — |
| Hamburg observatory (before 1909) | Alemania | Hamburgo | — |
| Hamburg-Georgswerder observatory | Alemania | Hamburgo | — |
| Hamburg-Himmelsmoor observatory | Alemania | Hamburgo | — |
| Hamilton Astronomical Observatory | Nueva Zelanda | — | 40 m |
 Hamilton Astronomical Society Observatory | Nueva Zelanda | — | 40 m |
 Hampstead Observatory | Reino Unido | Hampstead | — |
| Hanau Observatory | Alemania | Hanau | — |
| Hanggao Observatory | — | — | — |
 Hanging Rock Raptor Observatory | Estados Unidos | Condado de Monroe | — |
 Hankasalmi Observatory | Finlandia | Hankasalmi | — |
| Hans-Haffner-Sternwarte | Alemania | Hettstadt | — |
 Hans-Ludwig-Neumann-Sternwarte | Alemania | Distrito del Alto Taunus | — |
 Hans-Nüchter-Sternwarte | Alemania | Fulda | — |
| HAO observatory | Marruecos | Oukaïmeden | — |
| Happy Valley observatory | Nueva Zelanda | Wellington | — |
| Hard Labor Creek Observatory | Estados Unidos | Georgia | — |
 Harestua Solar Observatory | Noruega | Lunner | — |
| Harken Astronomical Observatory | Estados Unidos | Pewaukee | — |
| Harlingten Research observatory | Estados Unidos | Ánimas | — |
| Harlingten Telescope, Greenhill Observatory | Australia | Melton Mowbray | — |
 Harquahala Peak Observatory | Estados Unidos | condado de La Paz | — |
| Harrow observatory | Reino Unido | Municipio de Harrow | — |
| Hartebeesthoek Magnetic Observatory | Sudáfrica | — | — |
 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 | — |
| Hibiscus observatory | Francia | Puna'auia observatory | — |
| Hida Observatory | Japón | Takayama | — |
| Hidaka Observatory | Japón | Hidaka | — |
| Hidden Valley Observatory | Estados Unidos | Dakota del Sur | — |
| Higashi-Hiroshima Observatory | Japón | Higashihiroshima | — |
 Higginson Tower | Canadá | Champlain | — |
| High Altitude Observatory | Estados Unidos | South Kona | — |
| High Point observatory | Estados Unidos | High Point | — |
| High Resolution Fly's Eye Cosmic Ray Detector | Estados Unidos | Utah | — |
 High School, Academy Road, Stirling | Reino Unido | Stirling | — |
| Highland Road Park Observatory | Estados Unidos | Luisiana | — |
| Highworth observatory | Reino Unido | Highworth | — |
| Hilbre Bird Observatory | Reino Unido | — | — |
| Hill Town Local Studies Museum “Miku” | Japón | Prefectura de Hokkaido | — |
| HillTopTop observatory | Estados Unidos | Edgewood | — |
| Himalayan Chandra Telescope, IAO | India | Eugen Hänle | — |
| Hin Hua Observatory | Malasia | — | — |
 Hinode | — | — | — |
| HIPAS Observatory | Estados Unidos | Alaska | — |
 Hipparcos | — | — | — |
| Hirao Observatory | Japón | Hirao | — |
| Hiratsuka observatory | Japón | Hiratsuka | — |
 Hirsch Observatory | Estados Unidos | — | — |
 Hisaki | — | — | — |
 Hitomi | — | — | — |
| HOB Observatory | Italia | Capraia | — |
 Hohenpeißenberg Meteorological Observatory | Alemania | Hohenpeißenberg | — |
 Hoher List Observatory | Alemania | Daun | 504 m |
 Holcomb Observatory and Planetarium | Estados Unidos | Indiana | — |
 Holden Observatory | Estados Unidos | Siracusa | — |
| Holme Bird Observatory | Reino Unido | Norfolk | — |
| Holomon Observatory | Grecia | — | — |
| Homburg-Erbach observatory | Alemania | Erbach | — |
 Hondelage observatory | Alemania | Brunswick | — |
| Honjo observatory | Japón | Honjō | — |
 Honolulu Magnetic Observatory | Estados Unidos | Ewa Beach | 4 m |
 Hoober Observatory | Reino Unido | Yorkshire del Sur | — |
| Hoogeveen observatory | Países Bajos | — | — |
| Hope Observatory | Estados Unidos | Maryland | — |
 Hopkins Ultraviolet Telescope | — | — | — |
| Horizon observatory | Kazajistán | Petropavl | — |
| Hormersdorf Observatory | Alemania | Hormersdorf | — |
| Hornsby Bend Bird Observatory | Estados Unidos | Texas | — |
| Hornsund Magnetic Observatory | Noruega | Svalbard | — |
| Horus observatory | España | Cártama | — |
 Hoshi no Mura Observatory | Japón | Tamura | — |
| Hottviller observatoire | Francia | Hottviller | — |
| Houston observatory | Estados Unidos | Houston | — |
| Houstrup observatory | Dinamarca | Varde | — |
| Howell Observatory | Estados Unidos | Misisipi | — |
| Hoyerswerda observatory | Alemania | Hoyerswerda | — |
 Hradec Králové Observatory | República Checa | Hradec Kralové | 287 m |
| Huairou Solar Observing Station | República Popular China | — | — |
| Huancayo Magnetic Observatory | Perú | — | — |
| Hubelmatt Observatory | Suiza | Lucerna | — |
| Hudson observatory | Estados Unidos | Nuevo Hampshire | — |
| Huelva Observatory | España | Huelva | — |
| Huenfelden Observatory | Alemania | Hünfelden | — |
 Hume Cronyn Memorial Observatory | Canadá | London | 251 m |
| Hume Observatory | Estados Unidos | Mark West Springs | — |
| Hunters Hill observatory | Australia | Ngunnawal | — |
| Hurbanovo Magnetic Observatory | Eslovaquia | Hurbanovo | — |
| HUT observatory | Estados Unidos | Edwards | — |
| Hutton-Westfold Observatory | Australia | Victoria | — |
| Hvar Observatory | Croacia | Hvar | — |
| Hyde Memorial Observatory | Estados Unidos | Nebraska | — |
| Hyderabad Magnetic Observatory | India | Haidrābād | 500 m |
| Hypatia Observatory | Italia | Rímini | — |
 Hyper-Kamiokande | Japón | Hida | — |
| Hyperion Observatory | España | Caraquiz | — |
| Hésingue observatory | Francia | Hésingue | — |
 Höfingen observatory | Alemania | Leonberg | — |
| Hāwera Observatory | Nueva Zelanda | South Taranaki District | — |
 Ḥulwān | Egipto | Gobernación de El Cairo | 145 m |