In this study, using the base of coherent states, Landau diamagnetism has been generalized within Tsallis Thermostatistics. As far as we know, this is the first attempt to introduce coherent states in this formalism. The magnetization and the susceptibility of the system have been obtained and compared with the standard result to illustrate the effect of nonextensivity. Then, adding a perturbation term to the Hamiltonian of the system, nonextensive effects on diamagnetic susceptibility have been investigated. In addition to this, making use of the q(G)-deformed partition function of the q(G)-oscillator system, the magnetization for q(G)-deformed Landau diamagnetism has been derived, with the aim of comparing the results obtained within both formalisms.