This book constitutes the refereed conference proceedings of the 9th International Conference on Mobile Wireless Middleware, Operating Systems and Applications, MOBILWARE 2020, held in Hohhot, China, in July 2020. Due to COVID-19 pandemic the conference was held virtually.The 21 revised full papers were reviewed and selected from 69 submissions and are organized in tracks onMobilWare;Big data, data mining and artificial intelligence workshop; Blockchain and internet of things workshop.