This book constitutes the proceedings of the 6th International Conference on Business Intelligence, CBI 2021, which took place in Beni Mellal, Morocco, during May 27-29, 2021. The 26 full and 6 poster papers included in this book were carefully reviewed and selected from a total of 60 submissions. They were organized in topical sections as follows: decision support, information systems and NLP; big data, datamining, Web services and Web semantics; optimization and decision support; signal, image and vision computing; networking, cloud computing and networking architectures in cloud.