The Marihuana Tax Act of 1937, Pub. L.Tooltip Public Law  75–238, 50 Stat. 551, enacted August 2, 1937, was a United States Act that placed a tax on the sale of cannabis. The H.R. 6385 act was drafted by Harry Anslinger and introduced by Rep. Robert L. Doughton of North Carolina, on April 14, 1937. The Seventy-fifth United States Congress held hearings on April 27, 28, 29th, 30th, and May 4, 1937. Upon the congressional hearings confirmation, the H.R. 6385 act was redrafted as H.R. 6906 and introduced with House Report 792. The Act is referred to, using the modern spelling, as the 1937 Marijuana Tax Act. It was overturned in 1969 in Leary v. United States, and was repealed by Congress the next year.

Harry Jacob Anslinger was an American government official who served as the first commissioner of the U.S. Treasury Department's Federal Bureau of Narcotics during the presidencies of Herbert Hoover, Franklin D. Roosevelt, Harry S. Truman, Dwight D. Eisenhower, and John F. Kennedy. He was a supporter of Prohibition, and of the criminalization of all drugs, and spearheaded anti-drug policy campaigns.