The book focuses on the relevant basic concepts of Magnetic oxides, as well as on synthesis routes and important applications of spinel ferrites, hexaferrites and magnetic oxide nanomaterials. Keywords: Magnetic Oxides, Spinel Ferrites, Hexaferrites, Magnetoelectric Ceramic Composites, Soft Ferrites, Nano-Size Spinel Ferrites, Magnetic Nanoparticles, Device Miniaturization.