As the mobile communication technologies have experienced a great progress in recent years, mobile computing systems and sustainable informatics technologies have become an integral part in our daily lives. The recent tremendous development in these technologies ranging from mobile edge computing devices, to personalized, embedded and sustainable applications. The International Conference on Mobile Computing and Sustainable Informatics (ICMCSI 2021) organized by Pulchowk Campus, Institute of Engineering, Tribhuvan University, Nepal on 29-30 January 2021 has significantly contributed to address the unprecedented research advances in the areas of mobile computing and sustainable informatics. ICMCSI 2021 is dedicated to explore the cutting-edge applications of mobile computing and sustainable informatics to enhance the future of mobile applications. This international conference serves a forum for researchers to address mobile networks, computing models, algorithms, sustainable models, and advanced informatics that supports the symbiosis of mobile computing and sustainable informatics. The conference covers almost all the areas of mobile networks, computing and informatics.