Facile synthesis of PANI/PPY/CdS ternary nanocomposite resulting from the integration of polyaniline (PANI), polypyrrole (PPY) and CdS using chemical oxidative polymerization technique was carried out in the laboratory. The study included comparative investigation of CdS incorporated polyaniline (PANI/CdS) and CdS incorporated polypyrrole (PPY/CdS) binary nanocomposite with PANI/PPY/CdS. The embodiment of CdS into PANI and PPY proved to be very effective in enhancing the optoelectronic properties. The formations of synthesized materials were confirmed by XRD, FTIR and FT-Raman spectroscopic analyses. The optimized ternary nanocomposite showed reduced optical band gap (~ 1.48 eV) by UV–visible spectra analysis. Photoluminescence (PL) spectra showed the highest PL intensity for optimized PANI/PPY/CdS nanocomposite due to high non-radiative electron–hole recombination rate. Ohmic conductance (~ 0.114 S) for the optimized nanocomposite was obtained by J–V characteristics plot. The dielectric analysis confirmed that PANI/PPY/CdS ternary nanocomposite showed highest dielectric constant and low dielectric loss as compared to other binary nanocomposites. These optimized optical, electrical and dielectric properties confirmed that the as-prepared PANI/PPY/CdS nanocomposite can be used as an efficient electron transport layer for OLEDs application.