The tunnel magneto-resistance (TMR) ratio is investigated for spin-filter magnetic tunnel junctions (S-FMTJs) in the presence of spin–orbit coupling inside the spin-filter (SF) layer. The transmission probability is calculated by the non-equilibrium Green’s function formalism. It is shown that the TMR ratio can be tuned by the physical properties of the SF layer such as magnetization orientation and exchange splitting. S-FMTJs have also presented a higher TMR ratio compared to that in the conventional MTJs due to the presence of the SF layer. These findings can be utilized to improve the performance of the magneto-resistive random access memory in the field of spintronics.