The control problem for nonlinear systems, particularly those with constraints, has garnered substantial attention due to its practical and theoretical significant [4, 33, 40, 41, 45–47]. The constraints frequently encountered in engineering systems could influence the tracking performance, stability, and robustness of the control system. Typically, these constraints can be categorized into two types: system capability-related constraints [27, 32] (i.e., input saturation, communication resources, measurable information); and performance-related constraints [39, 42] (e.g., transient response, convergence rate, and steady-state behavior). In this book, we will discuss the control designs of Euler–Lagrange Systems, more general nonlinear systems and Multi-input Multi-output (MIMO) systems under single or multiple constraints. Hereafter, we will provide an overview of constrained nonlinear control designs under different scenarios.