Lighting consumes a significant amount of generated electrical power in developing countries, and it uses over 20% of the energy supplied in developed countries. Therefore, semiconductor-based light sources with high energy efficiencies are critical technologies for the reduction of global carbon footprint. As an emerging lighting technology, organic light-emitting diode (OLED) has received huge worldwide attention in recent years, partially driven by its success in the flat-panel display market and partially driven by its technology virtues such as an unique thin, flat, foldable form factor. In this review, we will provide an overview on the current status of OLEDs for lighting applications. Specifically, a detailed overview of the state-of-the-art white OLED design concepts including their working principles will be presented. A brief overview on the current status of out-coupling techniques suitable for white OLEDs will also be discussed.