Here, we report a unique hybrid sandwich-type composite structure consisting of waste cigarette wrapper (CW) inserted in polydimethylsiloxane (PDMS) and reduced graphene oxide (RGO) composite matrix that displays a high EMI shielding effectiveness (SE) of similar to 50.79 dB in the extended Ku-band. The function of the inserted CW is to facilitate the multiple reflections and heat dissipation as it contains an Al coating. The interior of CW in the composite as well as the three-dimensional conductive networks of RGO throughout the PDMS matrix facilitates the microwave absorption through conductive dissipation and heat dissipation. Thus, an absorption-multiple reflection-absorption pathway is followed due to the combination of three sandwiched layers, that is, PDMS-RGO, CW, and PDMS-RGO. The sandwich architecture of the hybrid PDMS nanocomposite containing both CW and RGO displays a superior EMI SE over the nanocomposite that only contains RGO as filler in PDMS matrix. Moreover, the fabricated composite displays a high thermal conductivity which helps to dissipate the radiated microwave energy via a Joule heating effect. Thus, the fabricated lightweight and flexible hybrid composite structure could be an efficient microwave absorber which offers an attractive and cost-effective alternative approach to metal based conventional EMI shielding materials.