The paper deals with the electronic impact of ancillary ligands on the varying redox features of azobis(benzothiazole) (abbt) in the newly introduced mononuclear ruthenium complexes [Ru(pap)2(abbt)]n (1n) and [Ru(bpy)2(abbt)]n (2n), where pap = 2-phenylazopyridine and bpy = 2,2'-bipyridine. In this regard, the complexes [RuII(pap)2(abbt•-)]ClO4 ([1]ClO4), [RuII(pap)2(abbt0)](ClO4)2 ([1](ClO4)2), [RuII(bpy)2(abbt0)](ClO4)2 ([2](ClO4)2), and [RuII(bpy)2(abbt•-)]ClO4 ([2]ClO4) were structurally and spectroscopically characterized. Unambiguous assignments of the aforestated radical and nonradical forms of abbt in 1+/2+ and 12+/22+, respectively, were made primarily based on their redox-sensitive azo (N═N) bond distances as well as by their characteristic electron paramagnetic resonance (EPR)/NMR signatures. Although the radical form of abbt•- was isolated as an exclusive product in the case of strongly π-acidic pap-derived 1+, the corresponding moderately π-acidic bpy ancillary ligand primarily delivered an oxidized form of abbt0 in 22+, along with the radical form in 2+ as a minor (<10%) component. The oxidized abbt0-derived [1](ClO4)2 was, however, obtained via the chemical oxidation of [1]ClO4. Both 1+ and 22+ displayed multiple closed by reversible redox processes (one oxidation O1 and four successive reductions R1-R4) within the potential window of ±2.0 V versus saturated calomel electrode. The involvement of metal-, ligand-, or metal/ligand-based frontier molecular orbitals along the redox chain was assigned based on the combined experimental (structure, EPR, and spectroelectrochemisry) and theoretical [density functional theory (DFT): molecular orbitals, Mulliken spin densities/time-dependent DFT] investigations. It revealed primarily ligand (abbt/pap or bpy)-based redox activities, keeping the metal ion as a simple spectator. Moreover, frontier molecular orbital analysis corroborated the initial isolation of the radical and nonradical species for the pap-derived 1+ and bpy-derived 22+ as well as facile reduction of pap and abbt in 1+ and 2+, respectively.