This book constitutes the proceedings of the 6th International Conference on the Internet of Vehicles, IOV 2019, which took place in Kaohsiung, Taiwan, in November 2019. The 23 papers presented in this volume were carefully reviewed and selected from 101 submissions. The papers focus on providing new efficient solutions with digital intervehicular data transfer and overall communications. Yet, IOV is different from Telematics, Vehicle Ad hoc Networks, and Intelligent Transportation, in which vehicles like phones can run within the whole network, and obtain various services by swarm intelligent computing with people, vehicles, and environments.