[en] As part of the summary of the Conceptual Design Activities (CDA) for the International Thermonuclear Experimental Reactor (ITER), this document describes the magnet systems for ITER, including the Toroidal Field (TF) and Poloidal Field (PF) Magnets, the Structural Support System and Cryostat, the Cryogenic System, the TF and PF Power and Protection Systems, and Coil Services and Diagnostics. After an Introduction and Summary, the document discusses the (i) Design Basis, including General Requirements, Design Criteria, Design Philosophy, and the Database (a.o., engineering data on key materials and components), and (ii) the Subsystem Design and Analysis, including Conductor Design, TF Coil and Structure Design, TF Structural Analysis, PF Coil and Structure Design, PF Structural Performance, Fatigue Assessment of Structures, AC Loss Performance, Thermohydraulic Performance, Stability, Cryogenic System, Power Supply Systems, and Coil Services. All magnets are superconducting, (based on Nb3Sn) except the Active Control Coils inside the Vacuum Vessel. The fault analysis has been taken to a level consistent with the design definition, showing that the present design meets the requirement for passive safety or can be made to meet it with only minor modifications. A more detailed assessment in this regard is needed but must await further development of the design. In conclusion, the magnet design concepts presently proposed can be developed into an engineering design. Refs, figs and tabs