Almost all magnetically ordered materials involve 3d or 4f elements. The late 3d metals and their alloys, including interstitial alloys and intermetallic compounds, are frequently ferromagnetic. Large magnetocrystalline anisotropy in 3d–4f inter-metallics, due mainly to the rare-earth, gives useful hard magnets. Conversely, the anisotropy can be reduced practically to zero in certain 3d alloys and, when magnetostriction is also vanishingly small, perfect soft ferromagnetism results. Oxides and other ionic compounds are usually insulators with localized electrons. There, anti-ferromagnetic superexchange coupling leads to antiferromagnetic or ferrimagnetic order. Some oxides, however, are metals, with the d-electrons forming a conduction band. Occasionally the 3d band is half-metallic. 44 representative materials are described, and some data is provided on 300 others. A few examples are included of magnetically-ordered materials that include neither 3d nor 4f electrons.