This book constitutes the refereed post-proceedings of the 9th International Conference on Mobile, Secure, and Programmable Networking, MSPN 2023, held in Paris, France, during October 26-27, 2023. The 15 full papers included in this book were carefully reviewed and selected from 31 submissions. They were organized in topical sections as follows vertical tools on machine leaning and artificial intelligence, network programming and Cloud computing, Industrial Internet of things, Digital Twins and Security.