Single-Atom Catalysts (SACs), containing under-coordinated single metal atoms bound on the surface of supports, have recently emerged as promising heterogeneous catalysts due to their intrinsic catalytic properties and efficient utilization (high dispersion) of noble metal atoms. Strong Metal-Support Interactions (MSIs) present in these catalysts can dictate the physicochemical properties, activity, and stability of SACs, which are significantly different from the conventional supported nanoscale metal catalysts. Although SACs exhibit unique catalytic behavior, their stability under catalytic operation is questioned due to the tendency of metals to sinter (aggregation). An optimal MSI can avoid metal aggregation and tune the stability and catalytic activity of SACs. Herein, we investigate MSIs of a series of transition metal atoms (Au, Cu, Ag,