Electrocatalytic organic synthesis has attracted considerable research attention because it is an efficient and eco-friendly strategy for converting energy sources to value-added chemicals. Defect engineering is a promising strategy for regulating the electronic structure and charge density of electrocatalysts. It endows electrocatalysts with excellent physical and physicochemical properties and optimizes the adsorption energy of the reaction intermediates to reduce the kinetic barriers of the electrosynthesis reaction. Herein, the recent advances related to the use of electrocatalysts for organic synthesis with respect to defects are systematically reviewed. The roles of defects in anodic and cathodic reactions, such as the syntheses of alkanes, alkenes, alcohols, aldehydes, amides, and carboxylic acids, are reviewed. Furthermore, the relationship between the defective structure and electrocatalytic activity is discussed by combining experimental results and theoretical calculations. Finally, the challenges, opportunities, and development prospects of defective electrocatalysts are examined to promote the development of the field of electrocatalytic organic synthesis. This review is expected to help understand the vital role of defects in catalytic processes and the controllable synthesis of efficient electrocatalysts for the production of high-value chemicals.