Today, waste/residual materials pose an extremely serious danger to the ecosystem. Such materials are widely used in a wide variety of engineering applications to reduce the negative effects of these waste/residual materials. In recent decades, researchers working on this issue, especially in geotechnical engineering, have started to use these waste/residual materials in soil improvement applications. In this study, the strength and thermal effect on cohesive soils reinforced with waste glass bottle powder (GP) were investigated. Clay soil (CS) mixed with GP at 5%, 10%, and 15% was compacted at optimum water content using standard proctor test. Mixture samples were cured for 7, 14, and 28 days. CS samples reinforced with GP were subjected to a series of unconfined compressive strengths after heating at three different temperatures (50, 80, and 110 degrees). From the experimental results obtained, the highest strength; was obtained in the CS+15 GP mixture for 28 days of curing and at 80 degrees heating temperature.