This book constitutes the refereed proceedings of three workshops symposia, held at the 40th International Conference on Conceptual Modeling, ER 2021, which were held virtually and in St. John's, NL, Canada, in October 2021. The 11 papers promote and disseminate research on theories of concepts underlying conceptual modeling, methods and tools for developing and communicating conceptual models, techniques for transforming conceptual models into effective implementations, and the impact of conceptual modeling techniques on databases, business strategies and information systems. The following workshops are included in this volume: Second Workshop on Conceptual Modeling for NoSQL Data Stores (CoMoNoS); 4th International Workshop on Empirical Methods in Conceptual Modeling (EmpER); and Second International Workshop on Conceptual Modeling for Life Sciences (CMLS).