Louis Joseph Gasnier (September 15, 1875 – February 15, 1963) was a French-American film director, producer, screenwriter and stage actor. A cinema pioneer, Gasnier shepherded the early career of comedian Max Linder, co-directed the enormously successful film serial The Perils of Pauline (1914) and capped his output with the notorious low-budget exploitation film Reefer Madness (1936) which was both a critical and box office failure.