The dataset contains tabular information about 1118 stakeholders (1079 unique entities) in 15 countries of Southeastern Europe that have been identified as Open Science stakeholders within the framework of the project NI4OS-Europe, funded by the European Commission under the INFRAEOSC-5b call. It was collected between November 2022 and the end of January 2023 based on the information provided by project partners from Albania, Armenia, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Georgia, Greece, Hungary, Moldova, Montenegro, North Macedonia, Romania, Serbia and Slovenia. It builds upon the dataset collected in 2019 as part of the NI4OS-Europe landscaping activity (Kosanović, Biljana, Ševkušić, Milica, & Otašević, Vladimir. (2020). Open Science stakeholders in Albania, Armenia, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Georgia, Greece, Hungary, Moldova, Montenegro, North Macedonia, Romania, Serbia and Slovenia [Data set]. Zenodo. https://doi.org/10.5281/zenodo.3766125). In November 2022, the project partners were invited to review and update this original dataset. The stakeholders are classified into five groups based on their role in the research ecosystem: FUND (research funders and policymakers), CREATE (universities, research institutes, etc.), SUPPORT (libraries, repositories, research infrastructures, etc.), CONSUME (organizations using research results in their work, e.g. SMEs) and FACILITATE (individuals and organizations involved in promoting the principles off open science). The dataset contains the following information for each entry: country, stakeholder category/role, official/legal name of the organization, city, Zipcode, addresses (street name and number), URL of the institutional website, geographic coordinates (latitude and longitude). ****Dataset contents**** NI4OS_Stakeholder_Map_20230222.csv, data file, comma-separated values NI4OS_Stakeholder_Map_20230222-README.txt, metadata, text format ****Column headers and field types*** Country (text) StakeHoldersRole (text, ItemList{fund,create,facilitate,consume,support}) InstitutionName (text) City (text) Zipcode (text) Address (text) URL (text-web address) Latitude (number.decimal(2,7)) Longitude (number.decimal(2,7)) Data from this dataset have been quality-checked by the NI4OS-Europe project team. We recommend these data for further use. The dataset was used to generate an interactive map: https://ni4os.eu/os-stakeholders-map// ****Dataset license**** The dataset is made available under the Creative Commons Attribution 4.0 International License (CC BY 4.0), https://creativecommons.org/licenses/by/4.0

NI4OS-Europe project is funded by the European Commission under the Horizon 2020 European research infrastructures grant agreement no. 8576