The 9th International Conference on Big Data Analytics (BDA 2021) will be held online during December 15-18, 2021. The conference will be organized by Indian Institute of Information Technology Allahabad, India. BDA 2021 provides an international forum for researchers and industry practitioners to share their original research results, practical experiences and thoughts on big data from different perspectives including storage models, data access, computing paradigms, analytics, information sharing and privacy, redesigning mining algorithms, open issues and future research trends.