This study aims to: (1) Determine the relationship between students’ perceptions and climate change mitigation behavior in the context of SDGs 13 (Climate Action), (2) Determine the relationship between students’ understanding and climate change mitigation behavior in the context of SDGs 13, and (3) Determine the simultaneous relationship between students’ perceptions and understanding toward climate change mitigation behavior among eleventh-grade students of SMAS Semen Padang. This study employed a quantitative approach with a correlational research design. The sample consisted of 60 eleventh-grade students of SMAS Semen Padang. Data were collected using a Likert-scale questionnaire that had been tested for validity and reliability. Data analysis techniques included descriptive analysis, Pearson Product Moment correlation, and multiple correlation analysis using SPSS version 26.0. The results showed that: (1) There was a positive and significant relationship between students’ perceptions and climate change mitigation behavior with a correlation coefficient of 0.329 and significance value of 0.010 < 0.05, (2) There was a positive relationship between students’ understanding and climate change mitigation behavior with a correlation coefficient of 0.210, but it was not significant because the significance value was 0.108 > 0.05, and (3) Simultaneously, students’ perceptions and understanding had a positive and significant relationship with climate change mitigation behavior with an R value of 0.332 and Sig. F Change of 0.036 < 0.05, although the relationship was categorized as low. The findings indicate that students’ climate change mitigation behavior is also influenced by other factors such as social environment, habits, and school support in implementing SDGs 13-based environmental education.