In the current study, two-layered AA7075-AA6061 friction stir lap welding (FSLW) joints have been fabricated successfully at the optimized process parameters of 850 rpm (tool rotational speed) and 55 mm/min (tool transverse speed), respectively. Different characterization techniques like field emission scanning electron microscope (FE-SEM), optical microscopy (OM), and X-ray diffraction (XRD) analysis have been utilized to observe the microstructural features and phases present in the stir zone (SZ). The SZ region consists of fine equiaxed grains owing to remarkable plastic deformation under the action of tool movement. Thermally mechanical affected zone (TMAZ) and heat affected zone (HAZ) region shows deformed and coarse grains, respectively. The microhardness study shows the SZ has higher microhardness than HAZ and TMAZ regions for both layers. Although SZ shows higher microhardness, it is still lower than their respective base metal (BM). This slight decrease in microhardness may be attributed to precipitate coarsening and annealing effects inside the SZ. SZ interfacial region shows appreciable strength and ductility owing to remarkable material mixing and interfacial joint. The ductile mode of failure is noted for all the samples. XRD analysis at the interface SZ region shows major peaks of the Aluminium phase with some minor peaks of Mg2Si. The minor peak of this Mg2Si intermetallics suggests that it did not influence the mode of failure at the interfacial region.