Atrial fibrillation (AF) is more prevalent in older adults than other populations and affects health-related quality of life (HRQoL). However, few studies have investigated HRQoL and clinical factors in older adults with AF. The aim of the current cross-sectional study was to describe HRQoL using an AF-specific QoL instrument and identify factors influencing HRQoL in Korean older adults with AF. Data from 205 patients diagnosed with AF in a tertiary hospital were analyzed. Patients' mean age was 74.24 years and 43.9% of patients were female. The total HRQoL score was 49.6 of 100. The lowest score was in the physical dimension of HRQoL. Concern about lethal complications from AF was an essential concept related to QoL. In multiple linear regression, age and gender were significant predictors for the physical dimension of HRQoL. Gender and comorbidity were significant factors for the sexual activity dimension. Health care providers should help improve the HRQoL of older adults with AF by reducing physical burdens and concerns about health-related complications.