Purpose: We tested the reliability and validity of the Self-Efficacy Questionnaire for Children (SEQ-C) in a sample of children living in orphanages in South Korea. Methods: Our study sample consisted of 334 children aged 13-18 obtained using a convenience sampling method. We conducted a confirmatory factor analysis to identify the factor structure of the 24 self-efficacy items and used a Pearson correlation to explore the scale's validity. Results: The findings show the SEQ-C is a reliable scale with a three-factor model measuring social, academic, and emotional self-efficacy. Construct validity was also supported by finding a significant negative correlation between self-efficacy and depression. Conclusions: Our study informs social workers and researchers that the SEQ-C measure is a useful tool for practical evaluation and intervention that can be used for children with disadvantaged socioeconomic backgrounds in South Korea.