We present a rapid (0.25‐1hr), method to produce functionalised allylsilanes from readily available vinylsilanes. Employing a Brønsted acid catalysed dehydration as the key step, allylsilanes are produced in good yields (22‐98%) and, in most cases, as a single geometric isomer. Furthermore, a possible alkylation‐Cope pathway was discovered for certain substrates and attempts to optimise this are described.