This review summarizes the recent advances in the chemistry of oxovanadium(III-V) mononuclear complexes and their linear assemblies bearing tetradentate Schiff base ligands. Structural parameters of the oxovanadium assemblies are compiled, which reveal the preference of specific coordination geometries around vanadium atoms according to the valence state. Emphasis is placed on the catalysis of multielectron redox reactions by oxovanadium(IV) complexes which disproportionate to vanadium(III) and oxovanadium(V) complexes under suitable conditions. Their biological implications and synthetic applications are described.