National or regional centers and professional, industrial, academic, and other non-governmental organizations specifically involved with developing, using, and/or promoting non-animal alternative methods for toxicity testing.
United States
American Society for Cellular and Computational Toxicology (ASCCT)
Cell Stress Society International
Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University
Center for Animal Alternatives Information, University of California, Davis, (UC Davis)
Environmental Bioinformatics and Computational Toxicology Center (ebCTC): US EPA funded research consortium of the University of Medicine and Dentistry Robert Wood Johnson Medical School, Princeton University, Rutgers University, US EPA’s National Center for Computational Toxicology, and US FDA's Center for Toxicoinformatics
In Vitro and Alternative Methods Specialty Section of the Society of Toxicology (IVAM)
Institute for In Vitro Sciences (IIVS)
Interagency Coordinating Committee on the Validation of Alternative Methods/ NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (ICCVAM/NICEATM)
International (Q)SAR Foundation
International Society of Regulatory Toxicology & Pharmacology
Society for In Vitro Biology (SIVB)
Society of Toxicology (SOT)
Europe
3R Research Centre 
Belgian Society of Toxicology and Ecotoxicology (BELTOX)
Biograf 3R: computational alternatives to animal testing
The Boyd Group (UK)
Center for Alternatives to Animal Testing - Europe (CAAT-Europe) (Germany)
Centre for Documentation and Evaluation of Alternatives to Animal Experiments (ZEBET), Federal Institute for Risk Assessment (BfR) (Germany)
Dutch-Belgian Society for In Vitro Methods (INVITROM)
European Centre for the Validation of Alternative Methods (ECVAM)
European Consensus Platform for Alternatives (ECOPA): includes 15 national platforms as full members and 1 associated platform†
European Partnership for Alternative Approaches to Animal Testing (EPAA)
European Society for Animal Cell Technology (ESACT)
European Society of Toxicology In Vitro (ESTIV)
EUROTOX: Federation of European Toxicologists & European Societies of Toxicology
Finnish Centre for Alternative Methods (FICAM)
Fund for the Replacement of Animals in Medical Experiments (FRAME)
Hepatocyte Users Group (HUG)
In Vitro Testing Industrial Platform (IVTIP)
In Vitro Toxicology Society (IVTS): affiliated with the British Toxicology Society
In Vitro Toxicology & Tissue Engineering Laboratory (Poland)
Italian Association for Toxicology In Vitro (CELLTOX)
Middle European Society for Alternative Methods to Animal Testing (MEGAT)
National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) (UK)
Norwegian Reference Centre for Laboratory Animal Science & Alternatives
Spanish Group on Alternative Methods (GTEMA)
Tissue and Cell Engineering Society (TCES)
Tissue Engineering and Regenerative Medicine International Society, European Chapter (TERMIS-EU)
Other Regions/International
ANZCCART, Animal Ethics Infolink (Australia)
Brazilian Centre for the Validation of Alternative Methods (BraCVAM) 
Canadian Council on Animal Care (CCAC)
International Cell Death Society
International Centre for Alternatives in Research and Education (I-CARE) (India)
International Council on Animal Protection in OECD Programmes (ICAPO)
International Society for Computational Biology (ISCB)
International Society for Computational Biology (ISCB) Student Council
Japanese Association for Animal Cell Technology (JAACT)
Japanese Center for the Validation of Alternative Methods (JaCVAM)
Japanese Society for Alternatives to Animal Experiments (JSAAE)
Korean Center for the Validation of Alternative Methods (KoCVAM)
Korean Society for Alternative to Animal Experiments (KSAAE)
Medical Advances Without Animals Trust (MAWA), Australia: working to establish Australian Centre for Alternatives to Animal Research (ACAAR) to be hosted by the Australian National University (ANU)