Purpose: This study investigated clinical competency, COVID-19-related anxiety, coping strategies, self-efficacy, and perceived stress among graduating nursing students during the COVID-19 pandemic. Methods: We conducted a cross-sectional survey. Participants were recruited from universities located in four major cities in South Korea. General demographic information, clinical competency, self-efficacy, perceived stress, COVID-19-related anxiety, and coping strategies were assessed using reliable questionnaires. Descriptive statistics, correlations, and multiple regression tests were used to analyze the data. Results: The mean clinical competency, self-efficacy, perceived stress, adaptive coping, and maladaptive coping were 138.16 ± 18.34, 83.85 ±14.02, 21.37 ± 5.79, 53.15 ± 4.64, and 30.98 ± 6.73, respectively. COVID-19-related anxiety was reported by 4.3% of participants. Clinical competency was significantly positively correlated with self-efficacy (r = .44, p < .001) and adaptive coping (r = .20, p = .035) and was significantly negatively correlated with maladaptive coping (r = .20, p = .035). The predictors of clinical competency were self-efficacy (β = .434, p < .001) and adaptive coping (β = .173, p < .039), which explained 23% of the variance in clinical competency. Conclusion Self-efficacy and adaptive coping strategies are significant predictors of clinical competence during the pandemic. Planning and implementing various curricular and non-curricular activities to increase senior students' self-efficacy and adaptive coping strategies will help prepare competent nursing graduates for the pandemic when they enter the nursing workforce.