Meeting science has advanced significantly in its short history. However, one-on-one (1:1) meetings have not been studied empirically as a focal topic despite making up nearly half of all workplace meetings. While some meeting science insights may apply to 1:1 meetings, others may not (or may function differently) due to conceptual, theoretical, and practical differences between meetings involving dyads and groups. Although 1:1 meetings come in various forms (e.g., peer-to-peer, employee-to-customer), we chose to use manager-direct report 1:1 meetings as an exemplar given their prevalence, theoretical relevance, and practical implications. In this paper, we first review some conceptual differences between dyads and groups. We then discuss how these differences likely manifest in the meeting context (before, during, and after meetings), and outline related propositions. Last, we leverage this conceptual framework and subsequent propositions to provide guidance for future research and theory on 1:1 meetings. In doing so, we hope this paper will act as the impetus for research and theory development on 1:1 meetings. Plain Language Summary Meeting science has flourished over the past two decades, with research and theory exploring best practices for leading and attending workplace meetings. However, a large portion of this research has focused on meetings of three or more people – despite the fact that meetings are often defined as a gathering between two or more people. Ignoring the one-on-one (1:1) meeting is a missed opportunity, as 1:1 meetings have a large presence in industry. It has been estimated that nearly half (47%) of all meetings are 1:1s, and these dyadic meetings often have unique purposes (e.g., performance appraisals) and involve different interactions (e.g., more interpersonal) outside of larger group meetings. Industry and practice have begun to explore these 1:1 meeting-especially meetings between managers and direct reports. For example, internal studies conducted at Microsoft and Cisco found that direct reports who had more frequent and effectively run 1:1 meetings with their managers were more engaged than their counterparts. While companies have seemingly acknowledged the importance of these meetings, research lags behind. Little empirical or theoretical investigations have explored 1:1 meetings. Yet, with the continued growth in the number of meetings worldwide, it is important to obtain empirical insights specific to 1:1 meetings. Doing so will help inform best practices when it comes to leading and attending 1:1 meetings. Thus, in this conceptual review of 1:1 meetings, we provide a future research agenda encouraging researchers (and practitioners) to investigate this unique (and important) meeting type – the one-on-one meeting between a manager and their direct report.