Organosilicon reagents are highly versatile and privileged scaffolds in modern synthetic chemistry, largely due to the range of transformations the groups are amenable to. The β-Silicon effect is one of the fundamental phenomena underpinning the inherent reactivity of organosilicon reagents, allowing unsaturated organosilanes to undergo a range of electrophilic substitutions with a variety of nucleophiles. The application of the β-Silicon effect in a range of organic transformations is reviewed with the discussion divided up based on the class of silane. The reactivity of these compounds towards carbon, heteroatom and metallic electrophiles is discussed from classical applications such as the Sakurai allylation to contemporary applications such as cross-coupling chemistry. In addition, examples of these transformations in the context of methodology development and natural product synthesis are provided.