<p>The large-scale emissions of CO₂ have led to a continuous rise in its concentration in the atmosphere, resulting in serious environmental and ecological problems, such as the greenhouse effect and climate change. As a result, there has been a significant increase in interest in theories, technologies, and methods related to CO₂ capture, conversion, and utilization, especially in achieving “carbon neutrality.” Among various carbon capture and utilization strategies, the biological process is an attractive option for converting CO₂ to valuable chemicals and fuels, offering remarkable reaction selectivity, efficiency, and mild reaction conditions. This review article reviewed and summarized various strategies for the biological conversion of CO₂. Specifically, more emphasis was given to in vitro enzymatic systems and microbial electrocatalytic system. We briefly introduced the background of biological CO₂ capture and utilization. Following this, the advancements in CO₂ reduction through the catalysis of single and multi-enzyme cascades were reviewed. We highlighted various approaches to improve the stability and activity of enzymes and develop cost-effective and sustainable reaction systems. Furthermore, the progress and application of microbial electrocatalytic CO₂ reduction were discussed. Finally, future developments and a perspective on biological CO₂ conversion are envisioned.</p>