Electro-fermentation combines microbial fermentation with controlled electrochemical loading to optimize biochemical production by improving redox stability. This chapter describes electro-fermentation as an advanced technology that can overcome the constraints of conventional fermentation, including energy efficiency, yield improvement, and resource utilization. Electro-fermentation allows for exact biofuel, organic acid, and specialty chemicals with few by-products through electrodes that control microbial metabolic pathways. Aspects include the electrical current, microbial and biocatalyst selection, and process optimization. As industries move toward more sustainable alternatives, electro-fermentation can provide a way forward to cost-effective, renewable-based biochemical production to support bioeconomy goals and address global climate change and waste issues.