The mechanical, thermal, electrical, reheology, and morphological properties of composites made from linear low-density polyethylene and carbon black (CB) content of 5%, 10%, and 20% by weight were investigated. The optimum mechanical and electrical properties performance was achieved with the adding of 5% carbon black. The drop in properties after adding more CB is due to agglomeration and poor dispersion of carbon particles in the polymer matrix. CB resulted in higher dynamic viscosity and storage modulus at low frequencies, although this phenomenon was reversed at high frequencies. CB resulted in more shear thinning of LLDPE at high shear rates.