Perovskite magnetism is the magnetic behavior exhibited by oxides with the general perovskite structure ABO3, in which transition-metal ions occupying the B-site sublattice—typically manganese, in the form of mixed-valent Mn3+ and Mn4+—couple magnetically through electron-exchange interactions mediated by intervening oxygen ions ^[1]. In doped perovskite manganites such as La1−xCaxMnO3, the transfer of an eg electron between neighboring manganese sites is favored when their core spins are aligned, a double-exchange mechanism that links ferromagnetic order to metallic conductivity. Because the magnetic state is coupled to the electronic, lattice, and orbital degrees of freedom, these materials undergo coupled paramagnetic-to-ferromagnetic and insulator-to-metal transitions near their Curie temperature, and an applied magnetic field can markedly reduce the resistivity—the phenomenon of colossal magnetoresistance ^[2]. The magnetism is thus not an isolated spin property but emerges from the interplay of mixed valence, orbital occupancy, lattice distortion, and exchange coupling within the ABO3 lattice. The concept is defined as the cooperative magnetic ordering of transition-metal cations in the perovskite crystal structure mediated by oxygen-mediated exchange ^[3].