In the last two decades, research on distributed filtering and control (FAC) has burgeoned into large-scale complex networks and systems. A distributed networked system, typically composed of a number of cost-effective dynamical nodes (agents) with limited sensing, computing, and communication capabilities, is gaining considerable popularity due to its low power consumption, simple installation, high performance, and strong reliability, as compared with the centralized setting. As a result, various network- induced FAC systems, techniques, and algorithms have emerged, including node registration and control, network consensus and synchronization, multi-sensor data clustering/fusion, network topological design and analysis, and the like. In addition, it is important to have an insightful understanding of the way networks and systems behave and evolve from the FAC perspectives. This is often critical with respect to many important problems, such as managing a limited number of sensors for the best field-of-view coverage, tackling the intrinsic interactions and unknown correlations among dynamical nodes, trade-offs between performance and constraints, or achieving automation in noisy environments, just to name a few. These problems are imperative but also challenging for their multidisciplinary nature and inherent complexity, for which various theories, techniques, and algorithms are continuously being proposed and developed; however, more research effort and endeavors are needed. This special issue is aimed at collecting high-quality papers in the research field of distributed filtering and control of complex networks and systems; the final result includes two comprehensive reviews and nine original research papers.