Falbo v. United States, 320 U.S. 549 (1944), was a case in which the Supreme Court of the United States held that a draft board's alleged error in classifying a Jehovah's Witness as a conscientious objector rather than a minister of religion is no defense to the board's order to report for national service; post-reporting review of the classification is sufficient due process.

The petitioner was indicted on November 12, 1942, in a federal District Court in Pennsylvania for knowingly failing to perform a duty required of him under the Selective Training and Service Act of 1940.

Admitting that his refusal to obey the order was wilful, the petitioner defended his conduct on the ground that he was entitled to a statutory exemption from all forms of national service since the facts he had presented to the board showed that he was a 'regular or duly ordained' minister.

On appeal, the petitioner urged that the District Court had erred in refusing to permit a trial de novo on the merits of his claimed exemption.

Such a denial is especially oppressive where a full hearing might disclose that the administrative action underlying the prosecution is the product of excess wartime emotions.