The synthesis and structural determination of a silver nanocluster Ag20{S2P(OiPr)2}12 (2), which contains an intrinsic chiral metallic core, is produced by reduction of one silver ion from the eight‐electron superatom complex Ag21{S2P(OiPr)2}12(PF6) (1) by borohydrides. Single‐crystal X‐ray analysis displays an Ag20 core of pseudo C3 symmetry comprising a silver‐centered Ag13 icosahedron capped by seven silver atoms. Its n‐propyl derivative, Ag20{S2P(OnPr)2}12 (3), can also be prepared by the treatment of silver(I) salts and dithiophosphates in a stoichiometric ratio in the presence of excess amount of BH4−. Crystal structure analyses reveal that the capping silver‐atom positions relative to their icosahedral core are distinctly different in 2 and 3 and generate isomeric, chiral Ag20 cores. Both Ag20 clusters display an emission maximum in the near IR region. DFT calculations are consistent with a description within the superatom model of an 8‐electron Ag135+ core protected by a Ag7{S2P(OR)2}125− external shell. Two additional structural variations are predicted by DFT, showing the potential for isomerism in such Ag20{S2P(OR)2}12 species. Chiral silver nanocluster: The structure of an intrinsically chiral Ag20 nanocluster was determinded. Containing a silver‐centered icosahedron capped by seven silver atoms, it was rationalized to be an eight‐electron superatom complex. Isomeric Ag20 cores with distinct symmetry were characterized in two derivatives (nPr C1; iPr C3). DFT was used to predict the presence of additional structural variations to show rich isomerism in the Ag20 metallic core.