Therefore, the present study aimed to investigate the effectiveness of flipped learning in Geographic Information Systems (GIS) instruction on students' interest in geography among Iraqi secondary school students. This study employed a quasi-experimental pretest–posttest control group design. The statistical population comprised secondary school students in Iraq, from whom 72 students were selected through convenience sampling and randomly assigned to an experimental group (n = 36) and a control group (n = 36). The experimental group received GIS instruction based on the flipped learning approach over 16 instructional sessions, whereas the control group received the same instructional content using the conventional teaching method. Data were collected using the Geography Interest Questionnaire, which measures four dimensions: Attention, Confidence, Relevance, and Satisfaction. Data were analyzed using descriptive statistics and multivariate analysis of covariance (MANCOVA) in SPSS version 26. The results indicated that, after controlling for pretest scores, the experimental group achieved significantly higher posttest scores in geography interest than the control group (p < .001). Furthermore, flipped learning had significant positive effects on all four dimensions of geography interest, namely Attention, Confidence, Relevance, and Satisfaction. The largest effect size was observed for the Attention dimension, whereas the smallest effect size was found for the Confidence dimension. The findings suggest that integrating flipped learning with GIS instruction enhances active learning, promotes classroom interaction, facilitates authentic and practice-based learning activities, and increases meaningful student engagement, thereby fostering students' interest in geography. Accordingly, this instructional approach can be considered an effective strategy for improving the quality of geography education in Iraqi secondary schools and is recommended for curriculum developers, geography teachers, and educational policymakers.