High transparency and conductive materials have captivated potential interest as transparent conducting electrodes (TCEs) in modern optoelectronic devices (e.g., solar cells). Several alternative TCEs have been developed in recent years to replace commercial ITO electrodes. This includes materials from transparent conductive oxides (TCOs) to novel electrodes made from doping with different metals/semiconductors and 2-D hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, and metal thin films. In this chapter, the most relevant TCEs developed to date are presented with their fundamental properties that are emphasized toward the applications for high-efficiency solar cells. The trade-off properties such as optical and electrical conductivity of various TCEs are discussed. The information provided will serve for selecting and developing suitable transparent electrodes according to specific application.