<p>This study presents a bibliometric analysis of research on open access and institutional repositories in the field of Library and Information Science (LIS). As scholarly communication has increasingly shifted toward digital dissemination, open science practices, and wider access to knowledge, the themes of open access publishing and repository development have become central to LIS research. In this context, the present study aims to map the intellectual structure, publication trends, and thematic evolution of this research domain. The analysis is based on 1860 English-language publications indexed in the Web of Science Core Collection and published between 2010 and 2025. Bibliometric methods were applied using VOSviewer and the Bibliometrix R package to examine annual publication growth, citation impact, prolific authors, influential institutions, leading countries, collaboration patterns, and keyword co-occurrence. The findings indicate a steady increase in scholarly output over time, reflecting growing global interest in open access policies, repository infrastructure, and changing models of scholarly communication. The results also reveal the prominence of a limited number of influential contributors and the emergence of major thematic clusters associated with digital repositories, academic visibility, research dissemination, and open knowledge systems. By providing a systematic quantitative overview of this body of literature, the study contributes to a better understanding of the development, structure, and future direction of research on open access and institutional repositories in LIS.</p>