The book Organic Light Emitting Diode (OLED) Toward Smart Lighting and Displays Technologies, edited by Laxman Singh, Rituraj Dubey, and Prof. R. N. Rai, strives to address the multiple aspects of OLEDs and their applications in developing smart lightings and displays. OLEDs have been used in almost all kinds of digital displays like those of mobile phones, laptops, tablets, phablets, TVs, etc., due to their outstanding features, including superior color quality, low cost, wide viewing angle, easy fabrication, mercury-free manufacture, tenability, stretchability, flexibility, etc. Investigations related to the synthesis of new organic materials and fabrication techniques have inspired us to write this book, which will fulfil the desire and thirst of OLEDs-based researchers.