The chapter discusses the principles and design of superconducting magnets, which can generate fields beyond 2 Tesla, the practical limit of normal-conducting magnets. The focus is on the coil-generated field, stored energy, and electromagnetic forces as key challenges in their design. The text covers magnetostatics, coil-dominated magnets, and the importance of field quality in particle accelerators. It also delves into the history of superconducting magnets, from early applications in beam lines to the development of high-field magnets for colliders. The chapter details the materials used, such as Nb-Ti and Nb3Sn for low-temperature superconductors (LTS), and BSCCO and ReBCO for high-temperature superconductors (HTS). It explains the scaling laws for coil dimensions, electromagnetic forces, and stress, and discusses methods for achieving pre-stress to maintain field quality and prevent quenches. The chapter concludes with an overview of current and future magnet development programs, including those for the High-Luminosity LHC (HL-LHC) and future colliders like the Future Circular Collider (FCC).The chapter discusses the principles and design of superconducting magnets, which can generate fields beyond 2 Tesla, the practical limit of normal-conducting magnets. The focus is on the coil-generated field, stored energy, and electromagnetic forces as key challenges in their design. The text covers magnetostatics, coil-dominated magnets, and the importance of field quality in particle accelerators. It also delves into the history of superconducting magnets, from early applications in beam lines to the development of high-field magnets for colliders. The chapter details the materials used, such as Nb-Ti and Nb3Sn for low-temperature superconductors (LTS), and BSCCO and ReBCO for high-temperature superconductors (HTS). It explains the scaling laws for coil dimensions, electromagnetic forces, and stress, and discusses methods for achieving pre-stress to maintain field quality and prevent quenches. The chapter concludes with an overview of current and future magnet development programs, including those for the High-Luminosity LHC (HL-LHC) and future colliders like the Future Circular Collider (FCC).