<p>This research investigates how lateral near-surface inhomogeneity affects three-dimensional (3D) electrical resistivity tomography (ERT) in terms of resolution and resolvability for Dipole–Dipole, Wenner-Schlumberger, and Joint arrays. Data from an archaeological site in Iraq, along with synthetic models, are used to evaluate the ability of these arrays in resolving underground-buried structures. The presence of lateral near-surface inhomogeneity (characterized by High-Low–High resistivity values) in the upper layer significantly impacts the measured apparent resistivity data. It tends to reduce the resolution and resolvability of the arrays and increase misfit error ratios, which can lead to serious interpretation issues for the 3D resistivity maps. This can lead to partial identification of underground structures. Under these conditions, both Dipole–Dipole and Joint arrays produce similar images, with a slight advantage to Dipole–Dipole as it provides the best resolution. Joint array exhibits a slight reduction in resolution, despite having higher data coverage and quality. Wenner-Schlumberger array provides the poorest resolution. When the upper layer is dominated only by high resistivity values, the resolution and resolvability of these arrays are significantly improved.</p>