As elementary education increasingly emphasizes student-centered and motivationally rich learning environments, the role of situational interest has gained attention as a key factor in enhancing both engagement and achievement. Despite its theoretical relevance, empirical research on how different types of interest-promoting strategies influence learning outcomes remains limited in classroom contexts. This study aims to address this gap by examining the effects of teachers’ situational interest promotion activities on elementary school students’ classroom engagement and academic achievement. Utilizing a quasi-experimental design, the study involved three sixth-grade classes in South Korea, each assigned to a different instructional strategy: Triggered Situational Interest (TSI), Maintained Situational Interest (MSI), and a combined TSI→MSI approach. Over four lessons on the topic of World Energy and Trade, differentiated instructional methods were applied. Data from engagement scales and academic achievement tests revealed that all groups improved significantly. However, the integrated TSI→MSI strategy yielded the greatest gains in both classroom engagement and achievement. These findings underscore the importance of combining initial attentioncapturing methods with sustained motivational supports to optimize learning outcomes.