Abstract Public libraries and public spheres have been widely studied over the past three decades. In recent years, several studies have comprehensively reviewed past research results to reveal the main issues, concerns, and research topics in the field of public libraries and public spheres. These studies have elucidated that the research theme of public libraries as a ‘meeting place’ has received increasing attention. They also noted the need for quantitative approaches in this field. Addressing this requirement, we conducted quantitative topic modelling using latent Dirichlet allocation and established an overview of research topics in the literature related to public libraries as public spheres. The following four periods emerged: first period (1993–2003), second period (2004–2010), third period (2011–2015), and fourth period (2016–2022). By analysing a cross-section of research topics from all periods, we elucidated the transitions of research themes developed in the research field. In addition, our comparison of topic model maps and topics over the years revealed that research topics appear to have become increasingly complex. Research topics on meeting places in public libraries have emerged continually and changed over time, covering (1) places for individual civic group activities, (2) public spaces where patrons face diversity and pluralism, (3) community spaces where patrons foster social trust, and (4) social spaces where patrons build social capital in the community. This result indicates that the research on public libraries as public spheres has gradually developed based on these venues being meeting places and will continue to progress.