This volume constitutes revised selected papers from the four workshops collocated with the 19th International Conference on Software Engineering and Formal Methods, SEFM 2021, held virtually during December 6–10, 2021. The 21 contributed papers presented in this volume were carefully reviewed and selected from a total of 29 submissions. The book also contains 3 invited talks. SEFM 2021 presents the following four workshops: CIFMA 2021 - 3rd International Workshop on Cognition: Interdisciplinary Foundations, Models and Applications; CoSim-CPS 2021 - 5th Workshop on Formal Co-Simulation of Cyber-Physical Systems; OpenCERT 2021 - 10th International Workshop on Open Community approaches to Education, Research and Technology; ASYDE 2021 - 3rd International Workshop on Automated and verifiable Software sYstem Development. Due to the Corona pandemic this event washeld virtually.