The Portico publishers that have chosen to include their content in Constellate are:
- Academy of Science of South Africa
- Begell House
- Berghahn
- BioOne
- Bond University
- The British Editorial Society of Bone & Joint Surgery
- Cambridge University Press
- Copernicus Publications
- CSIRO Publishing
- Edinburgh University Press
- EDP Sciences
- Edward Elgar Publishing
- Emerald Group Publishing
- F1000 Research
- Guilford Publications
- HBKU Press (QScience)
- Hindawi
- Indiana University Press
- International Association of Online Engineering
- The Institute for Business and Finance Research
- John Benjamins Publishing Company
- John Wiley & Sons, Inc.
- LED Edizioni Universitarie
- Michigan State University Press
- Microbiology Society
- Morgan & Claypool Publishers
- Nomos Verlagsgesellschaft mbH & Co. KG
- Nordic Open Access Scholarly Publishing
- Philosophy Documentation Center
- Pluto Press
- Project MUSE
- Royal Irish Academy
- The Royal Society
- SAGE Publications
- Society for Imaging Science & Technology
- Thieme Publishing Group
- Universitetsforlaget / Scandinavian University Press
- University of California Press
- University of Huddersfield Press
- University of Kansas Libraries
- University of South Florida
- Vittorio Klostermann