- Jack Baskin School of Engineering
- Jacobs University = Constructor University [Bremen]
- Jadavpur University
- James Watt School of Engineering [Univ Glasgow]
- Jamia Millia Islamia
- Janssen-Cilag [Issy-les-Moulineaux]
- Japan Advanced Institute of Science and Technology
- Japan Aerospace Exploration Agency [Sagamihara]
- Japan Atomic Energy Agency
- Japan Atomic Energy Agency [Ibaraki]
- Japanese French Laboratory for Informatics
- J. Craig Venter Institute [La Jolla, USA]
- Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy [Preston]
- Jerusalem College of Technology
- Jet Propulsion Laboratory
- Jeune Equipe Hémopathogènes Vectorisés
- Jianghan University
- Jiangsu University of Technology [Changzhou]
- Jinan University [Guangzhou]
- Jodrell Bank Centre for Astrophysics
- Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University
- Johannes Kepler Universität
- Johann Heinrich von Thünen Institut
- Johann Radon Institute for Computational and Applied Mathematics
- John Radcliffe Hospital [Oxford University Hospital]
- Johns Hopkins University
- Johns Hopkins University Applied Physics Laboratory [Laurel, MD]
- Johns Hopkins University School of Medicine [Baltimore]
- Johnson and Johnson Scios
- Johnson & Johnson Corporation
- Joint ALMA Observatory
- Joint ALMA Office
- Joint Institute for Nuclear Research
- Joint Laboratory for Petascale Computing [Illinois]
- Joint Research Center, Ispra, Italy
- Joint Robotics Laboratory
- Joseph Louis LAGRANGE
- Jozef Stefan Institute [Ljubljana]
- Jülich Supercomputing Centre
- Julius-Maximilians-Universität Würzburg
- JUNIA
- JustAI
- Justus-Liebig-Universität Gießen = Justus Liebig University