This volume, SGIoT 2020, constitutes the refereed proceedings of the 4th EAI International Conference on Smart Grid and Internet of Things, SGIoT 2020, held in TaiChung, Taiwan, in December 2020.The IoT-driven smart grid is currently a hot area of research boosted by the global need to improve electricity access, economic growth of emerging countries, and the worldwide power plant capacity additions. The 40 papers presented were reviewed and selected from 159 submissions and present broad range of topics in wireless sensor, vehicular ad hoc networks, security, blockchain, and deep learning.