The combined techniques of surface extended x‐ray absorption fine structure (SEXAFS) and high resolution core level photoelectron spectroscopy have been used to investigate the local bonding structure of the Sb/Si(111) interface. We find that the adsorption of 1 monolayer (ML) of Sb completely eliminates the surface components of the Si 2pcore level spectrum. The Sb induced Si 2pinterfacial core level has been found to be shifted 0.20±0.02 eV toward higher binding energy with an intensity that corresponds to the top 1 ML of surface atoms. The SEXAFS determination of the absolute surface coordination numbers and bond lengths within the first Sb shell is 2.1±0.3 Sb atoms at 2.86±0.02 Å and 2.0±0.4 Si atoms at 2.66±0.03 Å. Together, these results indicate that Sb trimers occupy the three fold atop sites of the Si(111) surface where each Sb atom is bonded to two Si atoms in a modified bridge configuration.