Objective: The aim of the present study was to explore whether or not cancer patients’ viral anxiety and depression during the coronavirus-2019 (COVID-19) pandemic were associated with a fear of cancer progression. We also assessed whether coping strategies affected the relationship. Methods: The present cross-sectional survey included cancer patients who visited Ulsan University Hospital in Ulsan, Korea. The participants’ demographic information and responses to the following symptoms rating scales were collected: Stress and Anxiety to Viral Epidemic–6; Patient Health Questionnaire–9; Cognitive Emotion Regulation Questionnaire-short version; or Fear of Progression Questionnaire-short version. Results: Of the 558 cancer patients surveyed, 25 (4.5%) reported that their treatment schedule was delayed during the COVID-19 pandemic. The patients’ fear of progression was found to be related to age (β=-0.08; p=0.011), viral anxiety (β=0.40; p<0.001), depression (β=0.26; p<0.001), and catastrophizing coping strategies (β=0.15; p=0.004), for an overall adjusted R2 of 0.46 (F=66.8; p<0.001). Mediation analysis showed that viral anxiety and depression were directly associated with fear of progression, while catastrophizing mediated this relationship. Conclusion Fear of progression in cancer patients was associated with viral anxiety, depression, and maladaptive coping techniques, such as catastrophizing, during the COVID-19 pandemic.