The new bidentate Schiff base ligand (L) named N1-(diphenylmethylene)naphthalene-1,8-diamine was prepared by the condensation reaction of benzophenone and 1,8-naphthylenediamine. The complexes with Mn(II), Ni(II), Zn(II), La(III), Er(III), and Yb(III) metal ions were prepared and characterized by using elemental analyses (C, H, N and M), FT-IR, 1H NMR, molar conductivity, magnetic moment, UV-Vis, mass and scanning electron microscope (SEM). The temperatures of decomposition of the Schiff base ligand and metal complexes were investigated using thermal analyses. The metal complexes were found to have the formulae [M(L)(H2O)3Cl]Cl.nH2O (M = Mn(II) (n = 4); Ni(II) (n = 2))], [Zn(L)(H2O)2Cl2] and [M(L)(H2O)2Cl2]Cl (M = La(III), Er(III) and Yb(III)) according to the elemental analyses data. The geometrical structure of all complexes was found to be octahedral. The molar conductivity of the complexes in DMF indicated the electrolytic nature of all complexes except Zn(II) complex was non-electrolyte. From the spectroscopic data, the Schiff base ligand acts as NN-bidentate ligand. The biological and anticancer activities of the Schiff base ligand and its complexes were investigated against two bacterial strains, two fungal strains and breast cancer cell line (MCF-7). Docking studies were performed to study the possible interaction between the Schiff base ligand with the active sites of the 3HB5 and 5JPE receptors.