- Jack Baskin School of Engineering
- Janusz Gil Institute of Astronomy [Góra, ul. Licealna 9, 65-417, Zielona Góra, Poland]
- Japanese French Laboratory for Informatics
- Japan Society for the Promotion of Science
- JDSU Uniphase
- Jet Propulsion Laboratory
- J. Heyrovsky institute of Physical Chemistry
- J. Heyrovsky Institute of Physical Chemistry
- Johann Bernoulli Institute
- Johann Bernoulli Institute of Mathematics and Computing Science
- Johann Radon Institute for Computational and Applied Mathematics
- John Curtin School of Medical Research [Canberra, Australia]