Purpose <p>This study examined the prevalence of fear of cancer recurrence (FCR) and its related factors among cancer survivors in South Korea.</p> Methods <p>Between August 2021 and November 2022, 345 cancer survivors were recruited from the National Cancer Center, regional cancer centers, university hospitals, and local communities in South Korea. Participants completed self-report questionnaires, including the Korean version of Fear of Cancer Recurrence Inventory-Short Form (K-FCRI-SF) via mobile platforms, and underwent structured diagnostic interviews using the Korean version of the Mini-International Neuropsychiatric Interview (K-MINI). Logistic regression analyses were conducted to identify key predictors of clinical FCR (K-FCRI-SF of ≥ 22).</p> Results <p>Overall, 60.87% of participants had elevated FCR, including 31.01% who met the threshold for clinical FCR. Younger age was independently associated with clinical FCR, whereas cancer-related clinical characteristics were not. Across domain-specific multivariable analyses, psychiatric comorbidities (illness anxiety disorder and somatic symptom disorder), psychological factors (thought suppression and catastrophizing), and cancer-related factors (symptom focusing, anxious preoccupation with cancer, negative illness perception, and illness-related ambiguity) were independently associated with clinical FCR.</p> Conclusions <p>These findings suggest the potential value of greater clinical attention to health anxiety and maladaptive cognitive responses as modifiable correlates of clinical FCR, alongside clearer and more consistent medical communication to address illness-related uncertainty. In comprehensive cancer survivorship, multidisciplinary approaches integrating cognitive-behavioral strategies with accurate medical guidance could be considered a promising avenue for reducing FCR; however, further longitudinal and intervention studies are needed to confirm these preliminary observations.</p>