The easy replacement of the hydroxy ligand in [Os3(CO)10(μ-H)(μ-OH)] by siloxy ligands affords a high-yield procedure to model compounds of the type [Os3(CO)10(μ-H)(μ-OSiR2R‘)] (R = Et, Ph; R‘ = Et, Ph, OH, OSiPh2OH), a springboard to better understand the reactivity of osmium carbonyl species on the silica surface. The new clusters [Os3(CO)10(μ-H)(μ-OSiPh2OH)] and [Os3(CO)10(μ-H)(μ-OSiPh2OSiPh2OH)], characterized by X-ray crystallography, represent the first molecular models of silica-anchored [Os3(CO)10(μ-H)(μ-OSi⋮)] having a ligand that mimics surface geminal and vicinal silanols, respectively.