Hydrogen-substituted silylium ions are long-sought reactive species. We report a protolysis strategy that chemoselectively cleaves either an Si-C(sp(2)) or an Si-H bond using a carborane acid to access the full series of [CHB11H5Br6](-)-stabilized R2SiH+, RSiH2+, and SiH3+ cations, where bulky tert-butyl groups at the silicon atom (R = tBu) were crucial to avoid substituent redistribution. The crystallographically characterized molecular structures of [CHB11H5Br6](-)-stabilized tBu(2)HSi(+) and tBuH(2)Si(+) feature pyramidalization at the silicon atom, in accordance with that of tBu(3)Si(+)[CHB11H5Br6](-). Conversely, the silicon atom in the H3Si+ cation adopts a trigonal-planar structure and is stabilized by two counteranions. This solid-state structure resembles that of the corresponding Bronsted acid.