Brett Leonard (born May 14, 1959) is an American film director, producer, and music video director specialising in the science fiction and horror genres. A few of his films, such as The Lawnmower Man (1992) and Virtuosity (1995), feature groundbreaking computer animation and visual effects.

Leonard's work with the IMAX 3D process set him apart from most directors, having gained early experience with this cutting-edge presentation medium directing T-Rex: Back to the Cretaceous in IMAX 3D. The film became the first number-one hit 3D movie to gross over $100 million worldwide (on IMAX screens alone).