Hosted by The Society for Modeling and Simulation International (SCS), the Annual Modeling and Simulation Conference (ANNSIM) is a new annual conference after merging SpringSim and SummerSim into a single conference starting in 2021. It is the flagship conference of SCS to cover state-of-the-art developments in Modeling & Simulation (M&S). We invite original contributions to the theory and practice of modeling and simulation in any scientific or engineering discipline.