In the past two decades, the field of social robotics has undergone significant growth, witnessing a surge in long-term human–robot interaction (HRI) studies. This review paper provides an in-depth analysis of 120 long-term HRI studies conducted between 2003 and 2023, spanning 7 major domains including education, entertainment, and physical and mental health. We define “long-term” as studies deploying social robots with the same users for more than three sessions across 3 consecutive days, aiming to employ a comprehensive approach and identify trends in this dynamic field. Our analysis explores various aspects of these studies, from participant demographics to the characteristics of the HRI and engagement measures. The findings reveal promising trends, such as diverse age group representation, a strong focus on real-world contexts, and autonomous robot operation. We also identify gaps, notably the limited representation of studies involving teenagers and those studying workplace settings. By presenting this overview, we aim to empower the HRI community to address challenges, refine methodologies, and foster innovation in the domain of long-term HRI.