In this study, we explored the development and characterization of fungus-immobilized foamed bacterial cellulose (FBC) scaffolds using Pleurotus ostreatus and Aspergillus oryzae. FBC, a porous biomaterial with high structural integrity and resistance to enzymatic degradation, served as a three-dimensional matrix for fungal cultivation. The results indicated effective fungal immobilization, with the 1% A. oryzae-immobilized FBC group (FBC/1A) achieving the highest production yield. The water content (97%) and swelling behavior (95.9%) analyses revealed that P. ostreatus-immobilized FBC maintained high hydration levels and rehydration capacities, whereas A. oryzae immobilization led to slightly reduced water retention. Morphological assessments via SEM confirmed the presence of fungal-derived fibers integrated with native cellulose structures, suggesting successful immobilization. A thermogravimetric analysis demonstrated enhanced thermal stability in fungus-immobilized FBC, particularly in the A. oryzae group, while FTIR spectra suggested possible structural alterations induced by fungal activity. Collectively, these findings support the potential of fungal-immobilized FBC as a robust, biodegradable material with promising applications in biotechnology and sustainable material development.