Flexible polymer composite films comprising carboxymethyl cellulose (CMC), polyaniline (PANI) and silver nanoparticles (AgNps) were successfully fabricated through an in-situ polymerization method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating the successful incorporation of AgNps into the CMC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNps into the CMC/PANI blend. The optical parameters such as band gap (Eg) was determined using the UV optical absorbance. The inclusion of AgNps and PANI has enhanced the optical properties of the CMC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications. The electrical properties of the composites were examined using temperature-dependent DC conductivity within 293–373 oK. The composites with increasing AgNps in the PANI-CMC composites shows the enhancement in the higher crystallinity, thermal stability, and higher electrical conductivity. the antimicrobial properties were evaluated with the aid of agar diffusion tests. The results showed distinct zones of inhibition against major microorganisms.