KIT-6 silica with well-ordered 3-D mesoporosity was developed as support for Mo, CoMo and NiMo catalysts. TEM and low-angle XRD analyses were used to ensure that the cubic Ia3d mesostructure is stable after Mo and promoter incorporation. The wide-angle XRD (as well O2-chemisorption analysis) was used to verify MoO3 (and MoS2) dispersion, with crystallite size <40 Å. The IR spectral studies were used to determine the nature of Mo species (octahedral and tetrahedral) and their growth with increasing Mo loading. TPR studies were also used to understand the nature of Mo species and their reducibility. A linear correlation was obtained between catalytic activities and oxygen uptakes suggesting that the increase in anion vacancies were responsible for the observed variation of hydrodesulfurization and hydrogenation activities. A comparison with γ-Al2O3 and SBA-15 supported catalysts shows superior activities of KIT-6 supported catalysts which is attributable to 3-D mesopore connectivity resulting in better catalyst dispersion, higher reducibility of Mo, and faster diffusion of reactant and products in the KIT-6 supported catalysts.