Semiconductor devices and methods of forming the same are provided. The semiconductor devices may include a substrate, a pair of semiconductor patterns adjacent to each other on the substrate, a gate electrode on the pair of semiconductor patterns, a source/drain pattern connected to the pair of semiconductor patterns, and a ferroelectric pattern on surfaces of the pair of semiconductor patterns. The surfaces of the pair of semiconductor patterns may face each other, and the ferroelectric pattern may define a first space between the pair of semiconductor patterns. The gate electrode may include a work function metal pattern that is in the first space.