A novel tetradentate Schiff base (I) synthesized from sulfametrole [N¹-(4-methoxy-1,2,5-thiadiazole-3-y1)sulfanilamide] and salciyldelyde forms stable complexes with transition metal ions such as Fe^(III), Fe^(II), Co^(II), Ni^(II), Cu^(II), Zn^(II), Cd^(II) and UO₂^(II) in absolute ethanol. Elemental analyses, IR, ¹HNMR, electronic spectra, magnetic moment, mass spectra and thermal analysis (TGA) were used to confirm the structures. From the elemental analyses data, the complexes were proposed to have the general formulae [M₂Cl₃(I)(H₂O)₅].YH₂O (Where M=Co^(II),Ni^(II),Cu^(II), Zn^(II) and Cd^(II), Y=0-3], [Fe₂Cl₅(I)(H₂O)₃]: 2H₂O, (FeSO₄)₂ (I)(H₂O)₄]:2H₂O and [(UO₂)₂ (NO₃)₃ (I) (H₂O)]:2H₂O. The molar conductance data reveal that all the metal complexes were non-electrolytes.  The IR, ¹HNMR, spectra show that ligand (I) is coordinated to the metal ion in a bidentate manner ON and via NO donor sites of the azomethine-N, phenolic-OH, enolic sulfonamide–OH and thiadiazole–N.  The magnetic and electronic spectra showed that the complexes exhibit octahedral geometry. The thermal behaviour of the complexes was studied.  All the prepared  compounds were screened for their antibacterial and antifungal properties and have exhibited potential activities