This book constitutes the thoroughly refereed post-conference proceedings of the Third  International Conference on Mobile, Secure and Programmable Networking, held in Paris, France, in June 2017. The 17 papers presented in this volume were carefully reviewed and selected from 35 submissions. They discuss new trends in networking infrastructures, security, services and applications while focusing on virtualization and cloud computing, network programming, software defined networks (SDN) and their security.