<p>Landslides and slope failures pose significant challenges due to unstable slopes, requiring sustainable and eco-friendly solutions to improve stability and minimize risks. These issues have become more frequent and severe due to improper land use, urbanization, and climate change. Traditional soil stabilization methods often rely on cement, which has environmental drawbacks such as soil erosion, water pollution, habitat destruction, and visual disruption, all of which harm ecosystems and biodiversity. This study investigates a sustainable alternative: a biopolymer-cement composite that partially replaces cement with biodegradable biopolymers to reduce environmental impact while maintaining structural performance. Guar Gum was tested as a biopolymer in varying concentrations (0.2%–1%), combined with different cement amounts. Laboratory experiments evaluated shear strength and permeability to determine the optimal mixture, and slope stability analyses using GEO5 software assessed the composite’s effectiveness. Results showed that the best shear strength occurred with biopolymer concentrations of 0.2%–0.4% and cement levels of 0.4%–0.5%, at moisture contents of 14% and 15.74%. A maximum factor of safety 2.12 was achieved with 1% biopolymer and 1% cement. These findings highlight the composite’s potential as a sustainable solution for slope stabilization.</p>