This study was motivated by the low level of social interaction skills among children residing in the Rusunawa Dormitory of Widya Mandira Catholic University, Kupang, as indicated by tendencies to withdraw from others, limited participation in group activities, difficulties in communication and cooperation, and a lack of self-confidence. This study aims to determine the effectiveness of the role-playing technique through group counseling in improving the social interaction skills of children at the Rusunawa Dormitory of Widya Mandira Catholic University, Kupang, in 2026. The study employed a quantitative approach using a pre-experimental method with a One-Group Pretest–Posttest Design. The population consisted of 108 dormitory residents, while the sample comprised eight children selected based on their pretest results and identified as having low levels of social interaction. Data were collected using a social interaction questionnaire. The intervention, consisting of the role-playing technique implemented through group counseling, was conducted in four sessions, with each session lasting 2 × 45 minutes. The results showed that the total pretest score of the eight respondents was 695 points, which increased to 1,133 points in the posttest, representing an improvement of 438 points. All respondents experienced a change in their social interaction category from low to high. Hypothesis testing using a paired-samples t-test yielded a significance value (two-tailed) of 0.000 < 0.05, with a calculated t-value of −28.040 and df = 7. Therefore, H₀ was rejected and Hₐ was accepted. Based on these findings, it can be concluded that the role-playing technique implemented through group counseling is effective in improving the social interaction skills of children at the Rusunawa Dormitory of Widya Mandira Catholic University, Kupang, in 2026.