Structural sealants are one of the most essential construction materials due to a rising demand of buildings having glass panel faćades. Silicones are the most preferred base component due to their excellent properties appropriate for structural applications. The effect of titanium dioxide (TiO2) nanofillers on the mechanical and thermal properties of commercially available silicone-based sealants was investigated. The incorporation of 1 wt% and 2 wt% of TiO2 has caused an increase on the elongation at break SSG4000E and SilPruf SCS2000N sealants while an increase on the modulus of resilience was observed at SilPruf SCS2000N with 1wt% TiO2. The elastic modulus was highest at 5 wt% TiO2 for all sealants. Swelling behavior decreased with increasing nanofiller due to the physical crosslinking effect, thus preventing the diffusion of the solvent into the material. Thermal stability also improved with the incorporation of 2 wt% TiO2 as observed in the increase of the onset temperature of decomposition.