The rapid expansion of settlements in the Southeastern region of Bangladesh has led to significant changes in Land Use and Land Cover (LULC), posing critical threats to biodiversity and ecosystem stability. This study quantifies and analyzes the spatial and temporal dynamics of Land Use and Land Cover (LULC) changes and their impacts on biodiversity in Cox’s Bazar, Bangladesh, from 2015 to 2025 using advanced geospatial techniques. It further predicts future LULC trends and evaluates their potential consequences for biodiversity conservation in the region.The area has witnessed unprecedented settlement expansion, especially after the influx of Rohingya refugees in 2017, leading to significant ecological disruptions. Utilizing multi-temporal satellite imagery from Landsat-8 & Landsat-9, four major LULC classification has been performed through supervised Classification.The classes have been identified and analyzed using ENVI for spatial pattern recognition. Change detection and prediction analysis for next 5 years have been conducted. The results of this study reveals a non-linear pattern of forest loss, predicting a 45.93% reduction in high density vegetation by 2030, contrasted with a 9.84% increase in built-up areas. The findings are supported by a highly dependable LULC classification, attaining an overall accuracy of 88.75% and a Kappa coefficient of 0.841, thereby substantiating the evaluation of biodiversity risks. In this study, biodiversity indicators were evaluated through Bayesian Time Series Analysis integrated with a Cellular Automata (CA) Markov Model. The application of GIS and remote sensing tools demonstrates their efficacy in tracking environmental changes and supports data-driven conservation planning in rapidly urbanizing regions.