AbstractTwo novel 3d (Ni)/4 f (Dy and Y) metal ions and polydentate organic ligands (H2L1 and H2L2) based tetranuclear coordination complexes, [(L1)4NiII2DyIII2(DMF)2(NO3)2]⋅DMF (1) and [(L2)4NiII2YIII2(DMF)2(NO3)2]⋅DMF⋅H2O (2), have been synthesized and characterized using IR, elemental analysis and single crystal X‐ray diffraction studies. The application of these complexes as C−C bond coupling homogeneous catalysts has been logically shown. The complex 1 acts as an excellent catalyst (with a very low catalyst loading of 0.17 mol%) for the syntheses of a wide range of bis(indolyl)methane derivatives in good yields using various indoles and aromatic/hetero aromatic aldehydes under optimized reaction conditions. A plausible reaction mechanism has been proposed showing the coordinative binding of the aromatic aldehyde at NiII centre along with the associative π‐stacking interaction between the ligand (H2L1) and the phenyl ring of the aromatic aldehyde and/or indole leading to the formation of the desired bis(indolyl)methanes under the metal assisted C−C bond forming reaction with subsequent elimination of water molecule in polar protic solvent.