Scanning tunneling microscopy (STM) has revealed numerous manifestations of nanoscale electronic disorder in the high-Tc superconductor Bi₂Sr₂CaCu₂O_8+d. The superconducting energy gap is found to vary over nanometer length scales for several dopings (McElroy et al, Cond/mat 0406491, PRL May 2005). Additionally, effects of scattered quasiparticles are found throughout the sample where no obvious scattering sites are present (K. McElroy et al., Nature 422, p520 2003). Finally, the low-bias topography shows long wavelength disorder which has been taken to imply nanoscale charge density variations. Randomness in dopant-atom distributions has long been suspected as a possible cause such atomic-scale electronic disorder, but it was impossible to test this conjecture directly. Here I will introduce new techniques allowing the first simultaneous imaging of dopant atom locations and atomic-scale electronic structure in a cuprate superconductor. They reveal directly how the dopant atoms (a) strongly influence all types of electronic disorder – principally by shifting spectral weight from low to high energy nearby, (b) do not produce significant charge density fluctuations, and (c) are the primary scattering centers associated with both quasiparticle interference effects and superconducting coherence peak suppression. I will discuss new insights into the nature of high Tc superconductivity which can be drawn from these observations.