The coastal regions of Bangladesh are highly dynamic and increasingly affected by both natural processes and human activities, leading to notable land formation and deformation. This study examines coastal land-use changes over the last three decades and predicts future trends using a Cellular Automata–Markov (CA–Markov) model. Focusing on Noakhali and Sandwip, the analysis shows a net land gain of 600.45 sq. km between 2000 and 2010, which declined to 297.10 sq. km during 2010–2020, alongside increased land deformation. Conversion from water to vegetation rose sharply from 27.97 sq. km to 109.62 sq. km over the same periods. Projections for 2030 indicate continued changes, with land area increasing to 1,934.22 sq. km and water area decreasing to 5,671.38 sq. km. The results highlight the influence of climate change, including sea-level rise and storm surges, and emphasize the value of predictive modeling for sustainable coastal management and planning.