Context From June 2020 to February 2021, a consortium of 10 organisations undertook a large-scale study on open access journals across the world that are free for readers and authors, usually referred to as “OA diamond journals”. This study was commissioned by cOAlition S in order to gain a better understanding of the OA diamond landscape. Presentation The study undertook a statistical analysis of several bibliographic databases, surveyed 1,619 journals, collected 7,019 free text submissions and other data from 94 questions, and organised three focus groups with 11 journals and 10 interviews with hosting platforms. It collected 163 references in the academic literature, and inventoried 1048 journals not listed in DOAJ. The results of the study are available in the following outputs: Findings Report - DOI: 10.5281/zenodo.4558704 Recommendations Report- DOI:10.5281/zenodo.4562790 References Library - DOI: 10.5281/zenodo.4562816 Journals Inventory - DOI: 10.5281/zenodo.4562828 Dataset - DOI: 10.5281/zenodo.4553103 Key Recommendations: Streamline technical support Ensure compliance with Plan S Build capacity Increase effectiveness Sustain and invest in the future Kick-start actions: Prepare an International Workshop and Symposium on OA diamond within 6 months to initiate a global conversation among different stakeholders Set up an OA diamond Funding Strategy within 1 year to implement funding recommendations Build the OA diamond Capacity Center within 2 years to support the implementation of recommendations

This report was supported by Science Europe and cOAlition S