Low volume fraction (0.5, 1, and 2 vol%) SiO2 reinforced magnesium nanocomposites were synthesized using powder metallurgy technique followed by hot extrusion. The nanocomposites were studied for physical, microstructural, ignition, and mechanical properties to study the influence of nanoparticulate addition on monolithic magnesium. The grain size of the developed nanocomposites was observed to marginally decrease with the addition of SiO2 nanoparticulates with 2 vol% SiO2 addition resulting in a grain size of ∼23 μm which is ∼32% lower than that of pure Mg. The ignition temperature of pure Mg was enhanced with the addition of SiO2 nanoparticulates with Mg 2 vol% SiO2 nanocomposite exhibiting an ignition temperature of 611 °C (∼20 °C greater than pure Mg and AZ31 alloy). Under room temperature tensile loading, Hall–Petch strengthening mechanism was the most dominant wherein the addition of SiO2 nanoparticulates to pure magnesium enhances the strength within 0–2 vol% range and ductility in 0–1 vol% range.