Electrochemical reduction of CO₂/CO (eCO₍₂₎R) powered by renewable electricity to produce value-added chemicals offers a promising pathway toward sustainable fuel production. Although advances in catalyst design and system engineering have enabled CO₂/CO electroreduction to achieve high current densities for generating hydrocarbons and oxygenates, the products remain largely limited to small carbon molecules (C₁–C₃). Recently, significant progress has been made in cascading eCO₍₂₎R with downstream reactions to expand the product spectrum toward polymeric or higher-value carbon products. However, comprehensive summaries and perspectives on these cascade systems remain scarce in the eCO₍₂₎R literature. This review systematically summarizes recent developments in cascade eCO₍₂₎R and downstream conversion. The advantages of integrating eCO₍₂₎R with additional reaction steps are analyzed, followed by a discussion of representative systems that couple eCO₍₂₎R with thermo-catalytic, biological, and electrochemical processes. Finally, the key challenges facing this emerging field are highlighted, along with perspectives on future research directions.