Growing global energy demand continues to drive fossil-fuel-derived carbon dioxide (CO₂) emissions. Electrochemical CO₂ reduction (eCO₂R) has attracted attention as a carbon cycle technology owing to its ability to operate under ambient conditions and use renewable electricity directly. The high thermodynamic stability of CO₂, competition with the hydrogen evolution reaction, and low product selectivity can be overcome with careful catalyst design. Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) offer porous structures and tunable metal active sites, enabling simultaneous control over CO₂ adsorption/activation, intermediate stabilization, and product desorption. Therefore, they hold promise as eCO₂R catalyst platforms. This paper summarizes the fundamental aspects of eCO₂R and then compares the product selectivity on MOF- and COF-based catalysts. On this basis, this study analyzed key design parameters, including the metal core composition, ligand electronics, and framework reconstruction, and developed guidelines for selecting an appropriate framework when a specific product is targeted. This review is expected to serve as a guide for the rational design of next-generation eCO₂R catalysts.