A new Schiff base ligand (E)-2-(((3 aminophenyl) imino)methyl)phenol (HL) has been synthesized by the reaction between m-phenylenediamine and 2-hydroxybenzaldehyde in 1:1 molar ratio. The structure of the ligand was characterized using different spectroscopic techniques. A new series of metal complexes of (HL) with La(III), Er(III) and Yb(III) have been synthesized. The structural features of the complexes have been obtained from their elemental analyses, molar conductivity, ESI-Mass, FT-IR, UV-VIS spectra, magnetic susceptibility, and thermogravimetric analysis (TG). The complexes were found to have 1:1 [M:L] stoichiometry. The infrared spectral studies reveal that HL behaves as a neutral tridentate ligand and coordinate to the metal ions via the azomethine nitrogen, protonated phenolic oxygen and nitrogen atom of the amine group.The presence of coordinated and hydrated water molecules in the complexes was confirmed by thermogravimetric analysis. All complexes possessed an octahedral geometrical structure as suggested from all the above techniques. The calculated binding energy values of the receptors of the colon cancer (PDB code: 2hq6) and the lung cancer (PDB code: 1x2j) were discussed. The ligand and the complexes were evaluated for their antibacterial and antifungal activity against gram positive bacteria, gram negative bacteria and fungi. The compounds showed effective antifungal and antibacterial activities against different microorganisms. Yb(III) complex showed the highest biological activity against most tested bacteria.