<p>Social contact data underpin research across public health, social and behavioral sciences, and network analysis, as interpersonal interactions shape population dynamics and societal outcomes. In South Korea, previous social contact surveys have been limited by small samples and restricted accessibility, often necessitating reliance on synthetic data from international studies. To address this gap, we conducted a large-scale national contact survey during winter 2023–24. A total of 2,415 individuals were recruited across age groups and regions, resulting in a final sample of 1,987 participants. The survey captured daily close contact behaviors during weekdays, weekends, school vacations, and holidays, along with demographic and contextual details. This study emphasizes transparency by documenting the entire process—from survey design to rigorous data cleaning and validation. The dataset provides comprehensive evidence on post-pandemic contact patterns in South Korea and supports applications in infectious disease modeling, public health policy analysis, and social network research. By sharing the methodology and dataset, we aim to establish a reproducible framework for future social contact surveys in South Korea and beyond.</p>