In this research, Additive Friction Stir Deposition (AFS-D), a nascent solid-state additive manufacturing (AM) process, is utilized to deposit magnesium alloy WE43. To determine the viability of the AFS-D process, a parametric study was completed, determining an acceptable parameter with minimal surface defects and being fully dense. Using this parameter, a bulk WE43 deposit was created to conduct an in-depth study of the microstructure, mechanical response, and fatigue behavior as compared to the feedstock material. The bulk WE43 deposit exhibited a refined homogenous microstructure compared to the feedstock material. However, the as-deposited WE43 experienced a decrease in hardness and monotonic mechanical response when compared to the feedstock. At high stress amplitudes, the fatigue life experienced a decrease compared to the feedstock, however overlapping of data occurred at lower stress amplitudes. This study illustrates the potential of AFS-D magnesium alloy WE43 in AM structural components.