Banana pseudostem bagasse (Musa spp.) is an abundant agricultural residue generated after harvesting or sap extraction. Its valorization contributes to reducing agricultural waste, replacing synthetic materials, and promoting the development of bio-based sectors in construction, packaging, and related industries. This study provides a comprehensive characterization of banana bagasse to support its use as a sustainable industrial material. The analysis focused on key physical, hydric, chemical, and thermal properties. The results showed a fineness of 40 µm, a density of 220 kg·m⁻³, a porosity of 77%, and a specific surface area of 1.2 m²·g⁻¹. Hydric properties included a moisture content of 74.5% (wet basis), a water retention capacity of 292.5%, and a water absorption of 122.5%. The chemical composition consisted of cellulose (41.6%), hemicellulose (28%), lignin (16%), pectin (5.7%), and ash content (3.7%), along with CHNO elemental composition. The calorific value was estimated at 3.7 MJ·kg⁻¹. All analyses were conducted according to standardized protocols (ISO, ASTM, AOAC, and NBN EN). These findings highlight the low density, high porosity, and balanced lignocellulosic composition of banana bagasse, making it a promising natural reinforcement for low-cost and sustainable applications. However, limitations such as moisture sensitivity, natural variability, and limited durability must be considered for effective implementation.