Objective The aim of this study was to explore whether psychological inflexibility in the elderly population is related to social-distancing phobia, and examine whether their viral anxiety, preoccupation with sleep, or intolerance of uncertainty may mediate the relationship.Methods Among the elderly population aged ≥65 in Korea, we conducted an anonymous online survey during January and February 2023. We collected the responses of 300 participants, collected demographic information, and symptoms using rating scales such as the Social-Distancing Phobia scale, Stress and Anxiety to Viral Epidemics-6 items (SAVE-6), Intolerance of Uncertainty Scale-12 (IUS-12), Acceptance and Action Questionnaire-II (AAQ-II), and Glasgow Sleep Effort Scale (GSES).Results Social-distancing phobia was expected by the SAVE-6 (β=0.34, p<0.001), IUS-12 (β=0.18, p=0.003), and GSES (β=0.18, p= 0.001) in the linear regression analysis. In the mediation analysis, psychological inflexibility did not directly influence social-distancing phobia. However, viral anxiety, intolerance of uncertainty, or preoccupation with sleep completely mediated the influence of psychological inflexibility on social-distancing phobia among elderly population.Conclusion The management of psychological inflexibility, intolerance of uncertainty, or preoccupation with sleep needs to be considered when designing interventions to address social-distancing phobia in elderly populations in future pandemics.