Presence of the hydrogen bonding near a metal center can influence the properties of the complex. Here, we describe changes in redox and spectral properties in discrete dioxo-molybdenum centers coordinated by a single thiolato ligand that can support an intra-ligand hydrogen bond. We have utilized thiophenolato ligands that can harbor hydrogen bonding between the thiophenolato sulfur with an amide functionality creating either a five- or a six-membered ring. Methylation of the amide functionality removes the NH⋯S hydrogen bonding thus providing a basis for understanding the effect of hydrogen bonding. These thiophenolato ligands have been used in synthesizing dioxo-Mo^VI complexes of type Tp*MoO₂(S-o-RC₆H₄), where R = CONHMe (11), CONMe₂ (12), NHCOMe (13), and N(Me)COMe (14). The complexes have been characterized by NMR, infrared, and UV-visible spectroscopy. Spectroscopic data clearly indicate the presence of hydrogen bonding in both 11 and 13, and stronger in 13, where hydrogen bonding stabilizes a five-membered ring. All complexes exhibit a Mo^VI/Mo^V redox couple and redox potentials are modulated by the nature of H-bonding. Compound 14 with the electron-releasing N(Me)COMe group has the highest reduction potential and is more difficult to reduce.