We report the photolumenses (PL) and dielectric measurements of Cd(1-x)CoxO nanocomposites with (0.00 ≤ x ≤ 1.00). It is found that an increase in x correlates with a significant change in crystallite size, particle size, porosity, Debye temperature, Young’s modulus, q-factor, binding energy, impedance of grains and their boundaries. The samples with x = 0.50 or 0.60 show an adverse change in the behavior of these parameters. We could not evaluate any shift in the wave length of PL emissions, although they are different in intensities. The samples of x = 0.40 and 1.00 show more visible emission colors at 640, 678, 716, and 791 nm. The x = 0.00 sample shows a negative dielectric constant (ε\ ), but it crossovers to positive for the other values of x. ε\ was gradually decreased as frequency increased up to 10 KHz, after which it nearly saturated except x = 0.80, in which it linearly decreased and never saturated. The ac conductivity decreased gradually against x such that the type of conduction is dependent on the chosen x. The Cole-Cole plot shows a straight line for x = 0.00 and arcs for x = 0.20 and 0.60, and a complete semicircular for x = 0.40, 0.50, 0.80 and 1.00. Furthermore, the effective capacitance was 9260 μF for x = 0.00, but it drops to 0.013 μF for x = 0.40, whereas the vice is true for bulk resistance. These results lend a reasonable certainty to the assertion that Co substitutes for Cd and make them potential prospects for devices such as diodes that emit light, cathode-luminescence displays, integrated circuits, Li-battery and supercapacitors