- Habitability, Atmospheres, and Biosignatures Laboratory
- Hacettepe University = Hacettepe Üniversitesi
- Halmos College of Natural Sciences and Oceanography
- Hamburger Sternwarte|Hamburg Observatory
- Hampton University
- Handix Scientific Inc.
- Hanscom Air Force Base
- Hansen Experimental Physics Lab [Stanford]
- Harvard John A. Paulson School of Engineering and Applied Sciences
- Harvard-Smithsonian Center for Astrophysics
- Harvard University
- Hatherly Laboratories [Exeter]
- Haute École spécialisée de Suisse occidentale = HES-SO University of Applied Sciences and Arts Western Switzerland = Fachhochschule Westschweiz [Schweiz]
- Haute résolution angulaire en astrophysique
- Hawaii Institute of Geophysics and Planetology
- Hayakawa Institute of Seismo Electromagnetics Co. Ltd.
- HD Rain
- Heinrich Heine Universität Düsseldorf = Heinrich Heine University [Düsseldorf]
- HELIOS - LATMOS
- Heliospace Corporation
- Héliosphère et Plasmas Astrophysiques
- Hellenic Space Center
- Helmholtz Centre for Ocean Research [Kiel]
- Helmholtz-Gemeinschaft = Helmholtz Association
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg
- Helmholtz zentrum für Schwerionenforschung GmbH
- Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research
- Helmholtz-Zentrum Geesthacht
- Helmholtz Zentrum München = German Research Center for Environmental Health
- Helsingin yliopisto = Helsingfors universitet = University of Helsinki
- Helsinki Institute of Physics
- Helsinki Observatory
- Helwan University [Caire]
- Henry M. Jackson Foundation for the Advancement of Military Medicine
- Hensoldt Space Consulting
- Herbiers universitaires de Clermont-Ferrand
- Heriot-Watt University [Edinburgh]
- Héritages et Constructions dans le Texte et l'Image
- Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences
- H. H. Wills Physics Laboratory [Bristol]
- High Altitude Observatory
- High-End Parallel Algorithms for Challenging Numerical Simulations
- Higher Technical School of Agricultural Engineering
- High Voltage Laboratory [Patras]
- H-ION Research, Development and Innovation Ltd.
- HIPE
- Hiroshima University
- HITCO Carbon Composites, Inc.
- HMCI
- Hochschule Luzern
- Hokkaido Bunkyo University
- Hokkaido Information University
- Hokkaido University [Sapporo, Japan]
- Honeybee Robotics Ltd
- Honeybee Robotics Spacecraft Mechanisms Corp.
- Hong Kong Baptist University
- Hong Kong University of Science and Technology
- Hôpital Ambroise Paré [AP-HP]
- Hôpital de la Timone [CHU - APHM]
- Hôpital Necker - Enfants Malades [AP-HP]
- Hôpital Paul Brousse
- Hôpital Raymond Poincaré [AP-HP]
- Hôpital Saint-Jacques
- Hopital Saint-Louis [AP-HP]
- Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest
- Hospices Civils de Lyon
- Howard University
- Huazhong University of Science and Technology [Wuhan]
- Hungarian Academy of Sciences
- Hungarian Meteorological Service
- Hungarian Solar Physics Foundation
- Hunterdon Central Regional High School
- HYBIS
- Hydro and Agro Informatics Institute
- Hydro-Climate Extremes Laboratory
- Hydroisotop GmbH
- Hydrologie-Hydraulique
- Hydrologie, Météorologie et Complexité
- Hydrometeorological observatory Anadyr
- Hydrometeorological Service [Georgetown]
- Hydrometeorology and Remote Sensing Laboratory
- Hydrosciences Montpellier
- Hydrosystèmes et Bioprocédés
- HYGEOS (SARL)