A magneto resistive random access memory (MRAM) device including a spin orbit torque structure including a stack of an oxide layer pattern, a ferromagnetic pattern, and a non-magnetic pattern; and a magnetic tunnel junction (MTJ) structure on the spin orbit torque structure, the MTJ structure including a stack of a free layer pattern, a tunnel barrier pattern, and a pinned layer pattern, wherein the spin orbit torque structure extends in a first direction parallel to an upper surface of the spin orbit torque structure, the ferromagnetic pattern includes a horizontal magnetic material, and the free layer pattern has a magnetization direction in a vertical direction perpendicular to the upper surface of the spin orbit torque structure, the magnetization direction being changeable in response to spin currents generated in the spin orbit torque structure.