This work investigates magnetic properties and the magnetocaloric effect in the scope of continuous and first-order phase transitions in different stability regimes of a system described by the Ashkin–Teller model. Mean Field Theory is implemented through the Gibbs–Bogoliubov variational principle to obtain expressions for free energy, entropy and magnetization, in addition to computing the magnetocaloric properties of the system under analysis. The starting point is a detailed analysis of magnetic properties as a function of temperature, coupling configurations and external fields. Continuous and first-order phase transitions are observed. The impact of having the system under the influence of an external field is studied, showing and discussing the most favorable conditions for the manifestation of the magnetocaloric potential. In addition, phase transitions between metastable and stable states due to the hysteresis effect when varying the external field are obtained from two different methods, Maxwell relations and the use of entropy variation to compute the correct magnetocaloric effect properties.