Selective conversion of two waste carbon resources—polyethylene and CO2—into valuable chemicals through tandem catalysis offers a promising way to recover resources. However, current systems often have low selectivity for light aromatics in the liquid products, leading to mixtures of linear and cyclic compounds that are hard to separate. In this study, we developed a one-step process using an oxide– zeolite catalyst (CuFeO2 + Ga-[Ga]/Zeolite Socony Mobil (ZSM)-5) at 400 °C and atmospheric pressure to produce separable liquid aromatics and CO from polyethylene and CO2 at the same time. The synergistic effect between cationic Ga species and Brønsted acid sites in Ga-[Ga]/ZSM-5 promotes dehydrogenation while reducing typical hydrogen-transfer reactions, resulting in significant H2 production. Meanwhile, the CuFeO2 component supports the reverse water–gas shift reaction, shifting the reaction equilibrium and increasing the formation of aromatics through better hydrogen utilization. This cascade catalytic system achieves 99% selectivity toward separable aromatics in the liquid products and 91.9% toward C1–C2 aliphatic hydrocarbons in the gaseous products. The yield of aromatics reaches 75.3 weight percent (wt%), with benzene, toluene, and xylene making up 81.1% of this fraction. Additionally, CO2 conversion reaches up to 10.9 mmol per gram of polyethylene. This strategy effectively turns waste plastics and CO2 into valuable products, offering a practical approach for waste valorization and CO2 utilization.