Reinforced concrete structures play a vital role in the infrastructure systems around the world, and their durability and serviceability hinge on the condition of the reinforcing steel. Cathodic Protection (CP) has proven to be a technique that can mitigate rebar corrosion in concrete structures regardless of their chloride content. The goal of this literature review was to synthesize the information on existing research related to the cathodic protection of rebars in concrete, which will be of great value for engineers involved in bridge design, bridge management, and structural maintenance, rehabilitation and preservation. This article includes knowledge of two types of CP technologies (ICCP and SACP), anode materials, methods of predicting anode service life and testing CP performance, monitoring techniques, thermally-sprayed zinc anode installation and replacement, and recent developments in CP technologies. In addition, this article covers the computational models to treat the transport of ions in concrete and of electrons within rebars of CP systems. Various boundary conditions necessary for CP prediction are systematically classified, which, in combination with the conservation laws of mass and electricity, can predict CP performance under various external conditions.