Abstract: The purpose of this paper is to provide a comprehensive picture of open access publishing in Finland. Data consists of the complete national peer-reviewed output of 48177 articles and books from 14 Finnish universities in 2016- 2017 stored in the VIRTA Publication Information Service. Each publication record contains an indication if it is openly available as Gold or Hybrid OA and/or if it is deposited in OA repository. Using this data, we investigate the share of openly available outputs across fields, as well as journal and book publishing, and analyse the open access status of all 10342 publication channels (journal/series and book publishers) used by Finnish researchers. We also examine the utility of international open access information sources, DOAJ and Bielefeld list for OA journals, and Sherpa/Romeo for self-archiving policies, in estimating the potential for open availability of peerreviewed outputs, as well as the importance of the largest international commercial publishers in light of these comprehensive national data.