Setting our bibliographic references free: towards open citation data Silvio Peroni Department of Computer Science and Engineering, University of Bologna, Italy ORCiD: 0000‐0003‐0530‐4305; E‐mail: silvio.peroni@unibo.it Alexander Dutton IT Services, University of Oxford, UK ORCiD: 0000‐0003‐1448‐3114; E‐mail: alexander.dutton@it.ox.ac.uk Tanya Gray Bodleian Library, University of Oxford, UK ORCiD: 0000‐0003‐1561‐7364; E‐mail: tanya.gray@bodleian.ox.ac.uk David Shotton Oxford e‐Research Centre, University of Oxford, UK ORCiD: 0000‐0001‐5506‐523X; E‐mail: david.shotton@oerc.ox.ac.uk Abstract Purpose. Citation data needs to be recognized as a part of the Commons – those works that are freely and legally available for sharing – and placed in an open repository. Design/methodology/approach. The Open Citation Corpus is a new open repository of scholarly citation data, made available under a Creative Commons CC0 1.0 public domain dedication and encoded as Open Linked Data using the SPAR Ontologies. Findings. The Open Citation Corpus presently provides open access to reference lists from 204,637 articles from the Open Access Subset of PubMed Central (OA‐PMC), containing 6,325,178 individual references to 3,373,961 unique papers. Research limitations/implications. We need tools, such as the CiTO Reference Annotation Tools and CiTalO, to facilitate the semantic enhancement of the references in scholarly papers according to Semantic Publishing models and technologies. Originality/value. Scholars, publishers and institutions may freely build upon, enhance and reuse the open citation data for any purpose, without restriction under copyright or database law. Keywords: Open Citation Corpus, SPAR Ontologies, CiTO, CiTalO, CiTO Reference Annotation Tool, citations, references, semantic publishing, open access